PLAB 1 (UKMLA AKT) gastroenterology & hepatology questions

In a young patient with typical reflux symptoms and no alarm features, a clinical diagnosis of GORD can be made and treated empirically. NICE guidance recommends a full-dose proton pump inhibitor for 4-8 weeks as first-line management in primary care. Endoscopy and pH monitoring are reserved for diagnostic uncertainty, treatment failure, or red flag features. H. pylori testing is primarily relevant for suspected peptic ulcer disease rather than straightforward reflux.

• A. pH monitoring is reserved for atypical or refractory cases, not initial management.
• C. H2-receptor antagonists are second-line, used when PPIs are ineffective or not tolerated.
• D. H. pylori testing is not routinely indicated for typical reflux symptoms without ulcer features.
• E. Endoscopy is not required in uncomplicated GORD without alarm symptoms.

Progressive dysphagia with unintentional weight loss in a patient over 55 years is a red flag warranting urgent investigation to exclude oesophageal or gastric malignancy. NICE guidance recommends a two-week-wait referral for direct access upper GI endoscopy in this situation. Delaying investigation with empirical treatment risks missing a potentially curable early-stage cancer. Barium swallow and ultrasound are not appropriate first-line investigations when endoscopy with biopsy is indicated.

• A. Ultrasound does not adequately assess the oesophageal mucosa and is not the appropriate initial test.
• B. Reassurance is inappropriate given the red flag features present.
• C. Empirical treatment delays diagnosis and is inappropriate with red flag symptoms.
• D. Barium swallow does not allow tissue biopsy and is not the first-line investigation when malignancy is suspected.

Barrett's oesophagus results from chronic GORD causing metaplastic transformation of the distal oesophageal squamous epithelium into columnar epithelium with intestinal metaplasia, which carries a risk of progression to dysplasia and adenocarcinoma. Surveillance endoscopy intervals are determined by segment length, with longer segments requiring more frequent surveillance, as per British Society of Gastroenterology guidance. This allows early detection of dysplastic change before progression to invasive cancer. Oesophagectomy is reserved for high-grade dysplasia or early cancer, not non-dysplastic Barrett's.

• A. Waiting for new symptoms misses the point of surveillance, which aims to detect asymptomatic dysplastic progression.
• B. Barrett's oesophagus without dysplasia still requires ongoing surveillance due to malignant potential.
• C. Oesophagectomy is not indicated for non-dysplastic Barrett's oesophagus.
• D. Doubling PPI dose does not reverse established metaplasia or remove the need for surveillance.

The combination of known cirrhosis, stigmata of chronic liver disease, ascites, and massive haematemesis with haemodynamic instability strongly suggests bleeding oesophageal varices secondary to portal hypertension. Peptic ulcer bleeds typically present with melaena or coffee-ground vomiting rather than exsanguinating fresh haematemesis, and lack features of chronic liver disease. Thrombocytopenia here reflects hypersplenism from portal hypertension rather than an isolated ulcer process. Urgent resuscitation and endoscopy with consideration of terlipressin and prophylactic antibiotics is required.

• A. Perforated ulcer presents with peritonitis and pain rather than massive haematemesis with liver stigmata.
• C. Erosive gastritis causes milder bleeding and is not associated with stigmata of chronic liver disease.
• D. Gastric cancer more commonly causes occult bleeding or iron deficiency anaemia rather than acute massive haematemesis.
• E. Mallory-Weiss tears typically follow forceful vomiting and cause smaller volume bleeds without chronic liver disease signs.

A Mallory-Weiss tear is a mucosal laceration at the gastro-oesophageal junction caused by a sudden rise in intra-abdominal pressure during forceful retching or vomiting, classically following an episode of severe vomiting such as from gastroenteritis or alcohol excess. It typically presents with small to moderate volume haematemesis occurring after an initial bout of non-bloody vomiting, and most cases are self-limiting. There are no stigmata of chronic liver disease to suggest varices, and the clinical picture lacks the severe chest pain and systemic illness seen in oesophageal rupture.

• A. Varices require portal hypertension, usually from chronic liver disease, which is absent here.
• B. Perforated ulcer causes acute severe abdominal pain and peritonism rather than bleeding after vomiting.
• C. Oesophageal rupture causes severe chest pain, subcutaneous emphysema, and systemic sepsis, not seen here.
• E. GORD-related oesophagitis is not typically precipitated acutely by a single episode of forceful vomiting.

The combination of dysphagia to both solids and liquids, regurgitation, and a barium swallow showing a dilated oesophagus with a smoothly tapering distal narrowing, the classic 'bird's beak' appearance, is highly suggestive of achalasia. Oesophageal manometry is the gold standard investigation and will confirm the diagnosis by demonstrating failure of lower oesophageal sphincter relaxation and absent peristalsis in the oesophageal body. Endoscopy is usually normal or near-normal in achalasia, as there is no mucosal pathology, which is why it does not confirm the diagnosis. PPI therapy and pH monitoring are irrelevant as this is not a reflux-driven process.

• B. Repeat endoscopy is unlikely to add diagnostic value when the initial study was normal and manometry is indicated.
• C. PPI therapy does not address the underlying motility disorder in achalasia.
• D. pH monitoring assesses acid reflux, not motility disorders like achalasia.
• E. CT is used to exclude secondary causes of pseudoachalasia but is not the diagnostic test of choice.

Both the urea breath test and stool antigen test rely on active H. pylori urease activity and bacterial load in the stomach, which are suppressed by proton pump inhibitors, causing false-negative results. NICE and BNF guidance recommend stopping PPIs for at least 2 weeks before testing for H. pylori by either method. If a patient cannot stop their PPI, testing should be deferred rather than performed early. Serum antibody tests are not recommended because they cannot distinguish past from current infection and remain positive long after eradication.

• A. Switching to another acid-suppressing drug does not solve the problem; H2 antagonists also need to be stopped before testing, and this adds an unnecessary step.
• B. Endoscopy is invasive and unnecessary in a patient without alarm features; non-invasive testing after an adequate washout is appropriate first-line.
• C. One day off the drug is not long enough; residual acid suppression will reduce bacterial urease activity and risk a false-negative result.
• D. Serology detects antibodies that persist after successful eradication, so it cannot confirm current infection and is not recommended for primary testing.

First-line H. pylori eradication in penicillin-non-allergic patients without recent clarithromycin exposure is a 7-day course of triple therapy with a PPI plus amoxicillin and clarithromycin (or metronidazole), as recommended by BNF and NICE CKS guidance. The PPI raises intragastric pH, enhancing antibiotic efficacy and promoting ulcer healing, while the two antibiotics act synergistically to eradicate the organism. Quadruple or fluoroquinolone-based regimens are reserved for treatment failure or penicillin allergy with prior macrolide exposure.

• A. Bismuth-based quadruple therapy is typically reserved for second-line or penicillin-allergic patients with prior clarithromycin exposure, not routine first-line use.
• B. A fluoroquinolone-based regimen is second-line, used after first-line treatment failure, not as initial therapy.
• C. A PPI with a single antibiotic is inadequate; dual therapy without a second antimicrobial gives unacceptably low eradication rates.
• E. This omits the PPI, which is essential for symptom control and to create the optimal pH environment for antibiotic activity.

Patients requiring long-term NSAID therapy who have a history of peptic ulcer disease are at high risk of recurrent ulceration and should be co-prescribed a proton pump inhibitor for the duration of NSAID use, per NICE and BNF guidance. PPIs reduce gastric acid secretion, promoting mucosal healing and reducing NSAID-related ulcer risk substantially. Gastroprotection should continue for as long as the NSAID is taken, not just during symptomatic periods, because ulceration can be asymptomatic until a complication such as bleeding occurs.

• B. Misoprostol is effective but causes diarrhoea and cramping, making it less well tolerated than PPIs, which are preferred first-line.
• C. Sucralfate is not recommended for NSAID ulcer prophylaxis and has largely been superseded by PPIs in current practice.
• D. A previous ulcer history, regardless of current H. pylori status, places this patient at high risk, so gastroprotection is indicated throughout NSAID treatment.
• E. H2 antagonists are less effective than PPIs for NSAID-associated ulcer prevention, and protection should be continuous, not symptom-triggered.

Sudden severe epigastric pain in a patient on regular NSAIDs, with a rigid, board-like abdomen, generalised guarding, tachycardia and free subdiaphragmatic gas on erect chest X-ray, is classic for a perforated peptic ulcer, most commonly duodenal. NSAIDs impair mucosal prostaglandin synthesis, predisposing to ulceration and perforation. Free intraperitoneal air confirms perforation of a hollow viscus and warrants urgent surgical referral for likely laparotomy or laparoscopic repair after resuscitation. Pancreatitis and cholecystitis do not typically cause pneumoperitoneum.

• A. Pancreatitis causes severe epigastric pain radiating to the back but does not produce free gas under the diaphragm.
• B. Mesenteric ischaemia classically causes pain disproportionate to examination findings, with a soft abdomen early on, not rigidity with free gas.
• C. Ruptured AAA typically causes hypotension with a pulsatile abdominal mass and flank or back pain, not free subdiaphragmatic gas.
• E. Cholecystitis causes right upper quadrant pain and fever but does not cause pneumoperitoneum or a rigid abdomen of this severity.

Recurrent, multiple or atypically located peptic ulcers that are refractory to standard therapy, especially with diarrhoea relieved by acid suppression and prominent gastric folds, raise suspicion for Zollinger-Ellison syndrome caused by a gastrin-secreting tumour. The initial investigation of choice is a fasting serum gastrin level, which is markedly elevated in this condition; if equivocal, a secretin stimulation test can be used for confirmation. Diarrhoea occurs because excess gastric acid overwhelms pancreatic bicarbonate buffering and damages the small bowel mucosa.

• A. Faecal calprotectin screens for inflammatory bowel disease, which does not typically cause multiple duodenal and jejunal ulcers.
• B. pH monitoring assesses gastro-oesophageal reflux disease and would not explain multiple refractory ulcers or diarrhoea.
• D. Amylase and lipase are used to diagnose pancreatitis, which does not present with recurrent peptic ulceration.
• E. Anti-tTG antibody testing is used for coeliac disease, which does not cause peptic ulceration or this clinical picture.

NICE guidance recommends that all patients with acute upper GI bleeding who require endoscopy, once haemodynamically stable, should undergo it within 24 hours of admission to allow timely diagnosis and endoscopic therapy where needed. Immediate endoscopy, after resuscitation, is reserved for patients who remain unstable despite resuscitation, such as those with ongoing massive bleeding. A Glasgow-Blatchford score above 0 indicates a need for admission and endoscopy rather than outpatient management, but this patient's stability means endoscopy can be scheduled within the standard 24-hour window rather than emergently.

• A. There is no specific NICE recommendation for a 6-hour window; stable patients are managed within 24 hours.
• B. This timeframe applies to unstable patients requiring immediate endoscopy after resuscitation, not a stable patient like this one.
• C. Waiting up to 48 hours risks delayed diagnosis and treatment and exceeds the NICE-recommended standard of 24 hours.
• D. A 72-hour delay is inappropriate and increases the risk of rebleeding and adverse outcomes; NICE specifies a 24-hour window.

In suspected variceal haemorrhage, NICE and British Society of Gastroenterology guidance recommend starting terlipressin and prophylactic broad-spectrum antibiotics immediately, before endoscopic confirmation. Terlipressin is a vasopressin analogue that causes splanchnic vasoconstriction, reducing portal pressure and variceal bleeding, while prophylactic antibiotics reduce the risk of bacterial infection and mortality in cirrhotic patients, who are prone to spontaneous bacterial peritonitis and sepsis after a variceal bleed. Both should be commenced promptly on clinical suspicion rather than delayed until endoscopy confirms the diagnosis.

• A. Octreotide is an alternative vasoactive agent used in some settings, but UK guidance favours terlipressin, and PPIs have no proven role in acute variceal bleeding.
• B. Propranolol is used for secondary prophylaxis after bleeding has resolved, not in the acute setting, and ciprofloxacin is not the recommended prophylactic antibiotic choice.
• C. Antibiotics should be started immediately on clinical suspicion, not delayed until endoscopic confirmation, because of the high risk of bacterial infection in cirrhotic patients.
• E. Tranexamic acid is not recommended in variceal bleeding, and vitamin K does not have a role in the acute management of this presentation.

The full (post-endoscopy) Rockall score combines clinical criteria (age, shock, comorbidity) with endoscopic findings (diagnosis and stigmata of recent haemorrhage) to predict rebleeding and mortality risk. Age is scored in bands (0 for <60 years, 1 for 60-79, 2 for ≥80), and comorbidities such as ischaemic heart disease add further points. Haemodynamic status (shock) and endoscopic stigmata like a visible vessel also increase the score. Haemoglobin, PPI dosing, time to admission and transfusion volume are not components of the Rockall score, even though they are clinically relevant to management.

• A. PPI dosing is not a Rockall variable; it is a treatment decision, not a risk score input.
• B. Transfusion volume is a treatment detail, not a scoring variable.
• D. Time to presentation is not included in the Rockall criteria.
• E. Haemoglobin is part of the Blatchford score, not the Rockall score.

In massive upper GI bleeding with haemodynamic instability (shock index features, hypotension, tachycardia) and a haemoglobin of 58 g/L, immediate red cell transfusion takes priority over waiting for further crystalloid, endoscopy or crossmatch completion. Uncrossmatched O-negative blood should be used if crossmatched blood is not immediately available, following a major haemorrhage protocol. Terlipressin should still be given for suspected variceal bleeding, but transfusion should not be delayed pending its effect. Balloon tamponade and endoscopy are used after initial resuscitation has begun, and excessive crystalloid can worsen dilutional coagulopathy and rebleeding.

• A. Large-volume crystalloid without blood products risks dilutional coagulopathy and does not correct oxygen-carrying capacity.
• B. Transfusion should not wait for formal crossmatch in life-threatening bleeding; uncrossmatched blood should be used.
• D. Endoscopy follows initial resuscitation and transfusion in an unstable patient, not before it.
• E. Balloon tamponade is a rescue measure after resuscitation and medical therapy, not a substitute for transfusion.

Crohn's disease characteristically causes skip lesions with patchy, discontinuous inflammation that can affect any part of the gastrointestinal tract from mouth to anus, often involving the terminal ileum, with frequent perianal disease such as fistulae or abscesses. Histology shows transmural inflammation and non-caseating granulomas, in contrast to ulcerative colitis, which causes continuous, superficial mucosal inflammation starting in the rectum and extending proximally without skip lesions or granulomas. The rectal sparing and skip lesions described here are inconsistent with ulcerative colitis. Infective, ischaemic and diverticular colitis do not typically present with granulomatous transmural disease and perianal fistulising features.

• A. Ulcerative colitis causes continuous mucosal inflammation starting in the rectum, not skip lesions with rectal sparing.
• B. Ischaemic colitis typically affects older patients with vascular risk factors and has a segmental but non-granulomatous pattern.
• C. Diverticular colitis occurs around diverticula, usually in the sigmoid colon, and does not cause ileal or perianal disease.
• E. Infective colitis is usually acute and self-limiting, without granulomas or chronic perianal disease.

This patient meets Truelove and Witts criteria for acute severe ulcerative colitis: more than 6 bloody stools per day plus at least one marker of systemic upset (temperature >37.8°C, heart rate >90/min, haemoglobin <105 g/L or ESR >30 mm/hour). Acute severe colitis is a medical emergency requiring hospital admission for intravenous corticosteroids, careful monitoring for toxic megacolon, and involvement of the gastroenterology and colorectal surgical teams. Outpatient management with oral aminosalicylates or steroids is inappropriate and unsafe in this setting, and colonoscopy is deferred because of the risk of perforation in acute severe disease; flexible sigmoidoscopy without full bowel preparation may be used cautiously.

• A. Full colonoscopy carries a perforation risk in acute severe colitis and is deferred until the acute episode is controlled.
• B. Oral mesalazine alone is inadequate for acute severe colitis meeting Truelove and Witts criteria.
• C. Acute severe colitis requires inpatient intravenous steroids, not outpatient oral treatment.
• E. Antimotility agents like loperamide risk precipitating toxic megacolon and are avoided in active severe colitis.

Aminosalicylates such as mesalazine are first-line for inducing remission in mild to moderate ulcerative colitis flares, acting topically on colonic mucosa to reduce inflammation via inhibition of prostaglandin and leukotriene synthesis. For left-sided or extensive disease, oral mesalazine is often combined with a rectal preparation to improve response, but oral mesalazine alone is appropriate first-line therapy here given the mild severity. Oral or intravenous corticosteroids are reserved for moderate-to-severe flares or those not responding to aminosalicylates. Biologics like infliximab are used in moderate-to-severe or refractory disease, and metronidazole has no established role in ulcerative colitis flares.

• A. Metronidazole is not indicated for ulcerative colitis; it has a role in some Crohn's perianal disease.
• B. Biologic therapy is used for moderate-to-severe or refractory disease, not a mild first flare.
• C. Oral corticosteroids are used for moderate-to-severe flares or aminosalicylate failure, not as first-line for a mild flare.
• E. Intravenous steroids are reserved for acute severe colitis requiring hospital admission.

Toxic megacolon is a life-threatening complication of severe colitis, defined radiologically by colonic dilatation (transverse colon diameter typically greater than 6 cm) together with systemic toxicity such as fever, tachycardia, altered mental state and hypotension. It carries a high risk of perforation and requires urgent involvement of gastroenterology and colorectal surgery, with consideration of escalation to rescue medical therapy (such as ciclosporin or infliximab) or emergency colectomy if there is no rapid improvement. Sigmoid volvulus produces a classic coffee-bean sign rather than diffuse dilatation with thumbprinting, pseudomembranous colitis relates to Clostridioides difficile infection, and pancreatitis and ischaemic colitis do not explain this combination of colonic dilatation and systemic toxicity in a patient with known severe colitis.

• A. Pseudomembranous colitis is caused by Clostridioides difficile and would not typically show this pattern in a patient already on steroids for colitis without preceding antibiotic exposure described.
• C. Ischaemic colitis typically occurs in older patients with vascular risk factors and does not cause this degree of toxic dilatation in known colitis.
• D. Acute pancreatitis presents with epigastric pain and raised amylase/lipase, not colonic dilatation on X-ray.
• E. Sigmoid volvulus shows a characteristic coffee-bean sign on imaging, not diffuse dilatation with thumbprinting.

Thiopurine methyltransferase (TPMT) metabolises azathioprine's active metabolite; patients with low or absent TPMT activity are at significantly increased risk of severe, potentially fatal myelosuppression if given standard doses. TPMT activity (or genotype) should be checked before starting azathioprine, with dose reduction or an alternative agent used in those with reduced activity, and the drug avoided in those with absent activity. Routine full blood count monitoring continues during treatment regardless of TPMT status, but TPMT testing is the specific pre-treatment safety check. Amylase is relevant to azathioprine-induced pancreatitis monitoring but is not the essential pre-treatment screening test, and hepatitis B status, HLA-B27 and faecal calprotectin are not required before starting thiopurines.

• A. HLA-B27 is associated with ankylosing spondylitis and inflammatory bowel disease but has no role in guiding thiopurine safety.
• B. Faecal calprotectin monitors disease activity, not azathioprine safety.
• C. Amylase can be checked if pancreatitis is suspected during treatment but is not the essential pre-treatment screening test.
• D. Hepatitis B status is relevant before starting biologic therapy, not specifically azathioprine.

Episcleritis is a common extraintestinal manifestation of inflammatory bowel disease, presenting with localised scleral redness, mild discomfort and photophobia but preserved vision and a normal pupillary response, and it typically correlates with intestinal disease activity. The accompanying tender erythematous nodules on the shins are consistent with erythema nodosum, another IBD-associated extraintestinal finding. Anterior uveitis and scleritis are also linked to IBD but cause more significant pain, photophobia and risk of visual impairment, with uveitis showing pupillary abnormalities and scleritis causing deep, boring pain with globe tenderness. Conjunctivitis and keratitis are not characteristic extraintestinal associations of IBD.

• A. Anterior uveitis typically causes more severe pain, photophobia and an abnormal, often constricted pupil.
• C. Conjunctivitis is not a recognised extraintestinal manifestation of IBD.
• D. Keratitis is not a typical extraintestinal association of IBD and usually involves corneal findings.
• E. Scleritis causes deep, severe pain and globe tenderness, often with vision affected, which is more severe than described here.

This patient meets the Rome IV criteria for irritable bowel syndrome: recurrent abdominal pain at least one day per week in the last three months, associated with defecation and a change in stool frequency or form, with symptom onset at least six months prior. She has no red-flag features (bleeding, weight loss, nocturnal symptoms, anaemia, raised inflammatory markers or family history) and her investigations, including calprotectin and coeliac serology, are normal. In the absence of alarm symptoms, a positive diagnosis of IBS can be made and symptomatic management started without further invasive investigation. Unnecessary investigation in clear-cut IBS causes delay, anxiety and cost without benefit.

• A. Calprotectin is already normal; a positive IBS diagnosis can be made now without delaying treatment.
• B. There are no red-flag features suggesting malignancy, so a two-week-wait referral is not appropriate.
• C. CT imaging is not indicated in straightforward IBS without alarm features.
• E. Colonoscopy is unnecessary when Rome IV criteria are met and no red-flag features or abnormal investigations are present.

Loperamide is the first-line antimotility agent recommended for IBS patients with diarrhoea-predominant symptoms, as it slows intestinal transit by acting on opioid receptors in the gut wall, reducing stool frequency and improving consistency. It should be titrated to achieve a target of one to two soft, formed stools per day. Laxatives such as senna, macrogol and lactulose are used for constipation-predominant IBS, not diarrhoea, and would worsen this patient's symptoms. Linaclotide is reserved for constipation-predominant IBS unresponsive to first-line laxatives.

• A. Linaclotide is used for constipation-predominant IBS, not diarrhoea-predominant symptoms.
• B. Senna is a stimulant laxative used for constipation-predominant IBS and would worsen diarrhoea.
• D. Lactulose is a laxative used for constipation and would exacerbate this patient's loose stools.
• E. Macrogol is an osmotic laxative for constipation and is inappropriate for a patient with diarrhoea.

The histological hallmark of coeliac disease is villous atrophy (flattening of the normally finger-like villi), crypt hyperplasia, and an increase in intraepithelial lymphocytes, reflecting a T-cell-mediated immune response to gluten in genetically susceptible individuals. These changes are most pronounced in the duodenum and proximal small bowel and typically improve on a gluten-free diet, which supports the diagnosis retrospectively. Marsh classification is used to grade the severity of these changes. Biopsy findings are combined with positive serology to confirm the diagnosis, as per NICE guidance.

• B. Normal villous architecture would exclude active coeliac disease on biopsy.
• C. Eosinophilic infiltration is characteristic of eosinophilic gastroenteritis, not coeliac disease.
• D. Granulomas with transmural inflammation are characteristic of Crohn's disease, not coeliac disease.
• E. Intestinal metaplasia is associated with chronic gastritis or Barrett's oesophagus, not coeliac disease.

This patient has signs of complicated diverticulitis with likely perforation and sepsis: generalised peritonism, absent bowel sounds, tachycardia, hypotension, fever and markedly raised inflammatory markers and lactate. Urgent CT abdomen and pelvis with contrast is the investigation of choice to confirm perforation, identify free air or abscess formation, and guide management, and should be obtained promptly alongside early surgical referral and sepsis management (including the Sepsis Six). Complicated diverticulitis with perforation or abscess often requires surgical intervention, such as laparotomy with resection, in addition to broad-spectrum intravenous antibiotics and fluid resuscitation. Outpatient management or oral antibiotics would be dangerously inadequate in this unstable, septic patient.

• A. Colonoscopy is contraindicated in acute complicated diverticulitis due to the high risk of perforation and is not urgent in this context.
• B. Oral antibiotics and discharge are inappropriate for a patient with signs of septic shock and suspected perforation requiring urgent inpatient management.
• C. Plain X-ray has poor sensitivity for diagnosing perforation or abscess compared with CT and is insufficient in a critically unwell patient.
• E. Conservative outpatient management is inappropriate and dangerous in a patient with signs of peritonitis and septic shock.

The classic pattern of periumbilical pain migrating to the right iliac fossa, anorexia, low-grade fever, guarding at McBurney's point and a positive psoas (hip extension) sign with a raised white cell count and CRP is characteristic of acute appendicitis. The migration of pain reflects visceral (periumbilical, referred via the midgut) to parietal (localised, from peritoneal irritation) pain transmission. A negative urine dipstick makes a urinary cause less likely. Diagnosis in adults is usually clinical, supported by inflammatory markers, with imaging (ultrasound or CT) used if the diagnosis is uncertain.

• A. Ureteric colic typically causes loin-to-groin colicky pain with haematuria on dipstick, not a migratory pattern with guarding.
• C. Meckel's diverticulitis can mimic appendicitis but is far rarer; appendicitis remains statistically and clinically the most likely diagnosis with this presentation.
• D. Mesenteric adenitis is a diagnosis of exclusion in children with preceding viral illness, less likely in a 22-year-old with this examination picture.
• E. Diverticulitis classically affects the sigmoid colon causing left iliac fossa pain, and is uncommon in a patient this young.

The NHS bowel cancer screening programme invites all adults aged 54 to 74 to complete a home faecal immunochemical test (FIT) every 2 years, which detects trace amounts of human haemoglobin in stool as a marker of possible colorectal neoplasia. FIT has replaced the older guaiac-based faecal occult blood test due to higher sensitivity and specificity for colorectal cancer. A positive FIT result prompts referral for colonoscopy for further investigation. This is a population-based screening test for asymptomatic average-risk adults, distinct from diagnostic colonoscopy used when red flag symptoms are present.

• A. One-off flexible sigmoidoscopy (bowel scope) screening at age 55 has been phased out and is not the current national screening strategy.
• C. CT colonography is not used for population screening and is reserved for specific diagnostic indications or when colonoscopy is incomplete or contraindicated.
• D. Screening is specifically offered to asymptomatic average-risk adults in the eligible age range; absence of symptoms does not exclude her from screening.
• E. Colonoscopy is not the first-line screening tool in the NHS programme; it is used as a follow-up investigation after a positive FIT result.

Vitamin B12 bound to intrinsic factor (secreted by gastric parietal cells) is absorbed specifically in the terminal ileum via cubilin-mediated receptor uptake; resection or disease of this segment removes the only site where this absorption occurs, leading to B12 deficiency regardless of intact gastric or dietary intake. This causes macrocytic anaemia and subacute combined degeneration of the spinal cord, explaining her peripheral neuropathy and ataxia. Management is lifelong intramuscular hydroxocobalamin replacement, as oral B12 cannot bypass the missing absorptive site. Small bowel bacterial overgrowth can also deplete B12 in Crohn's disease but is a secondary, less direct mechanism than loss of the absorptive site itself.

• A. Intrinsic factor is produced in the stomach, not affected by terminal ileal resection; this would cause pernicious anaemia, a different mechanism.
• B. This describes an iron deficiency mechanism, which would cause microcytic not macrocytic anaemia, and does not explain the neurological signs.
• C. Iron is absorbed in the duodenum and proximal jejunum, not affected by terminal ileal resection, and would cause microcytic anaemia.
• E. Bacterial overgrowth primarily depletes B12 (by competitive uptake) rather than folate, and is not the primary mechanism after ileal resection.

Chronic pancreatitis, commonly caused by long-term alcohol excess, leads to progressive destruction of pancreatic acinar tissue and reduced secretion of digestive enzymes including lipase, which is essential for breaking down dietary triglycerides into absorbable fatty acids and monoglycerides. Undigested fat passes into the stool, causing steatorrhoea: pale, offensive, floating stools that are difficult to flush. Pancreatic calcification on imaging is a classic finding in chronic pancreatitis. Treatment is with oral pancreatic enzyme replacement therapy (such as Creon) taken with meals, alongside abstinence from alcohol.

• A. Villous atrophy describes coeliac disease, not consistent with pancreatic calcification on imaging.
• B. Bacterial overgrowth can cause steatorrhoea via bile salt deconjugation, but this is not the mechanism suggested by pancreatic calcification and chronic alcohol history.
• C. Bile salts aid fat emulsification but are not primarily reduced in chronic pancreatitis; the liver and biliary system are not directly affected by this condition.
• D. Gastric acid aids protein digestion and some fat emulsification, but reduced acid secretion is not the mechanism in chronic pancreatitis with pancreatic calcification.

This patient has multiple high-risk features for refeeding syndrome: BMI under 16 kg/m² and little or no nutritional intake for more than 10 days, meeting NICE criteria for high risk. Refeeding syndrome occurs when reintroducing carbohydrates after starvation triggers a surge in insulin release, driving potassium, phosphate and magnesium intracellularly, causing severe hypophosphataemia, hypokalaemia and hypomagnesaemia despite normal pre-feeding levels. NICE guidance recommends starting nutritional support at a reduced rate (around 5-10 kcal/kg/day) in high-risk patients, with daily monitoring and correction of electrolytes, alongside thiamine and vitamin B co-strong supplementation before and during feeding to prevent Wernicke's encephalopathy. Rapid full-rate feeding in such patients risks cardiac arrhythmia, cardiac failure and death.

• A. Thiamine should be given before and during refeeding in at-risk patients to prevent Wernicke's encephalopathy, not withheld.
• B. Starting at full calorie requirements in a high-risk patient risks precipitating severe refeeding syndrome; weekly monitoring is too infrequent in the critical early refeeding period.
• C. Parenteral nutrition is not first-line when enteral feeding is possible, and starting at full rate in a high-risk patient is dangerous regardless of route.
• E. Prolonged delay is unnecessary and dextrose alone can still precipitate refeeding syndrome; cautious feeding with monitoring is the correct approach, not complete avoidance.

The hydrogen breath test is the standard non-invasive investigation for lactose intolerance: after an oral lactose load, undigested lactose is fermented by colonic bacteria producing hydrogen, which is absorbed and exhaled, measured as a rise in breath hydrogen concentration. The clinical pattern described, symptoms specifically triggered by lactose-containing dairy with tolerance of low-lactose hard cheese, together with normal coeliac serology and faecal calprotectin excluding coeliac disease and inflammatory bowel disease, strongly suggests lactose intolerance due to lactase enzyme deficiency. Management is dietary lactose restriction, with lactase enzyme supplements as an option, rather than complete dairy avoidance which can risk calcium and vitamin D deficiency.

• A. Small bowel biopsy is invasive and used to diagnose coeliac disease or other mucosal pathology, not first-line for suspected lactose intolerance.
• B. This describes testing for a cow's milk protein allergy, an IgE-mediated condition distinct from lactose intolerance, which is an enzyme deficiency.
• D. Abdominal ultrasound has no role in diagnosing a carbohydrate malabsorption disorder like lactose intolerance.
• E. Stool culture investigates infective causes of diarrhoea, not relevant to this chronic, dairy-triggered symptom pattern.

Current guidance (NICE and British Society of Gastroenterology) recommends that patients with mild gallstone pancreatitis undergo cholecystectomy during the same hospital admission once they have clinically improved, as delaying surgery significantly increases the risk of recurrent pancreatitis, biliary colic or cholecystitis while awaiting surgery. ERCP is reserved for cases with evidence of common bile duct obstruction or cholangitis, which this patient does not have. Index-admission cholecystectomy reduces readmissions without increasing complication rates compared with interval surgery.

• A. There is no evidence of duct obstruction or cholangitis to justify ERCP here.
• B. Delaying definitive treatment risks recurrent pancreatitis before cholecystectomy can be arranged.
• D. Waiting 6 months unnecessarily exposes the patient to further biliary events; same-admission surgery is preferred when she has recovered.
• E. Medical dissolution therapy is not used in the management of gallstone pancreatitis.

Acute cholecystitis presents with persistent (not colicky) right upper quadrant pain lasting more than a few hours, fever, and local peritonism (guarding, Murphy's sign) with a raised white cell count and CRP, reflecting gallbladder wall inflammation. Liver function tests are typically normal or only mildly deranged because the common bile duct is not obstructed. Biliary colic lacks fever and inflammatory markers, while cholangitis requires evidence of biliary obstruction with jaundice, which is absent here.

• A. The pain pattern and signs are localised to the right upper quadrant rather than epigastric with radiation to the back, and amylase/lipase would be needed to confirm.
• B. Choledocholithiasis implies duct stone obstruction, which would typically cause deranged liver enzymes and bilirubin.
• C. Cholangitis requires jaundice from biliary obstruction, which is absent and liver function tests are normal.
• D. Biliary colic causes intermittent pain without fever or raised inflammatory markers.

Charcot's triad (fever, jaundice, right upper quadrant pain) indicates ascending cholangitis due to biliary obstruction, usually from a common bile duct stone. Reynolds' pentad adds hypotension and altered mental status to the triad, signifying severe, suppurative cholangitis with septic shock, which is a surgical and endoscopic emergency requiring urgent biliary decompression (ERCP) alongside resuscitation and antibiotics. This patient already has confusion and hypotension, so he fulfils Reynolds' pentad and needs urgent senior review and source control.

• A. Rebound tenderness suggests peritonism but is not a pentad component.
• C. Shoulder tip pain is associated with gallbladder or diaphragmatic irritation, not part of the pentad.
• D. Haematemesis is not a component of Reynolds' pentad.
• E. Peripheral oedema is not part of Charcot's triad or Reynolds' pentad.

Transabdominal ultrasound is the first-line investigation for suspected gallstone disease because it is widely available, inexpensive, avoids radiation, and has high sensitivity for detecting gallstones within the gallbladder. It can also assess gallbladder wall thickness and bile duct diameter, helping to identify complications such as cholecystitis or duct dilatation. MRCP, endoscopic ultrasound and HIDA scans are reserved for cases where ultrasound is inconclusive or duct stones are suspected despite a normal scan.

• A. MRCP is more expensive and used as a second-line test when duct stones are suspected but not seen on ultrasound.
• C. HIDA scanning is used to assess gallbladder function or diagnose acute cholecystitis when ultrasound is equivocal, not as a first-line test.
• D. CT is less sensitive than ultrasound for gallstones and involves ionising radiation.
• E. Endoscopic ultrasound is invasive and reserved for further characterisation of suspected choledocholithiasis.

Chronic pancreatitis progressively destroys pancreatic acinar tissue, leading to exocrine insufficiency with reduced secretion of digestive enzymes, particularly lipase, which impairs fat digestion and causes steatorrhoea. The same process can destroy islet cells over time, leading to pancreatogenic (type 3c) diabetes, as seen in this patient. Pancreatic calcification and ductal dilatation on imaging are classic findings of chronic pancreatitis. Management of the malabsorption involves pancreatic enzyme replacement therapy (e.g. Creon) alongside dietary and diabetic management.

• A. Pancreatic polypeptide has a minor regulatory role and its loss does not explain steatorrhoea.
• B. There is no evidence of biliary obstruction here; the imaging findings point to pancreatic parenchymal and ductal disease.
• C. Bile salt deficiency causes fat malabsorption in cholestatic liver disease, not chronic pancreatitis.
• E. Bacterial overgrowth can cause steatorrhoea but is not the primary mechanism in chronic pancreatitis with calcification and duct changes.

Painless jaundice with weight loss and a palpable, non-tender gallbladder (Courvoisier's sign) is a classic presentation of pancreatic head cancer causing biliary obstruction, and NICE guidance (NG12) recommends urgent direct access CT scan or a suspected cancer pathway referral for anyone aged 60 or over with weight loss and any of a range of symptoms including jaundice. Early recognition is essential because pancreatic cancer has a poor prognosis and timely staging investigations determine resectability. Delaying referral through routine pathways risks disease progression and loss of curative surgical options.

• A. A 6-week wait is inappropriate given the urgency of these red flag features.
• B. There is no fever, rigors or right upper quadrant pain to suggest cholangitis, and antibiotics do not address the underlying obstruction.
• C. Painless jaundice with weight loss is a red flag requiring urgent, not routine, investigation.
• D. Routine referral delays diagnosis in a patient with features highly suspicious of malignancy.

This liver function test pattern shows a disproportionate rise in alkaline phosphatase and GGT relative to a near-normal ALT, which indicates a cholestatic pattern of liver injury, typically from biliary obstruction or intrahepatic cholestasis such as primary biliary cholangitis. Pruritus and fatigue are classic associated symptoms of cholestasis due to accumulation of bile salts. A hepatocellular pattern would show ALT markedly elevated out of proportion to ALP, reflecting hepatocyte injury rather than impaired bile flow. Normal albumin and prothrombin time indicate preserved synthetic liver function, excluding liver failure.

• A. Haemolysis causes isolated unconjugated hyperbilirubinaemia with normal ALP and GGT, not this pattern.
• B. Isolated unconjugated hyperbilirubinaemia, as in Gilbert's syndrome, would not be accompanied by raised ALP and GGT.
• D. Synthetic function is preserved with normal albumin and prothrombin time, so there is no liver failure.
• E. A hepatocellular pattern would show ALT rising markedly higher relative to ALP, which is not seen here.

A paracetamol level taken between 4 and 24 hours after an acute, single ingestion that falls on or above the treatment line on the nomogram is an indication to start intravenous N-acetylcysteine (NAC) immediately. NAC replenishes hepatic glutathione stores, allowing safe conjugation of the toxic metabolite NAPQI and preventing hepatocyte necrosis. Activated charcoal is only useful within 1 hour of ingestion, which has been missed here. There is no role for delaying treatment to repeat the level or simply observing once the level is above the treatment line.

• B. Methionine is an oral antidote historically used in some settings but is not the standard UK treatment; IV NAC is first-line.
• C. Activated charcoal is only effective if given within 1 hour of ingestion; this patient presented at 5 hours.
• D. Observation alone is inappropriate once the level is above the treatment line, as hepatotoxicity risk is significant.
• E. Treatment should not be delayed; a level above the treatment line is itself the indication to start NAC now.

A Maddrey's discriminant function score of 32 or more indicates severe alcoholic hepatitis with significant short-term mortality risk, and corticosteroids (typically prednisolone 40 mg daily for a limited course) have been shown to improve short-term survival in this group once active infection has been excluded. This patient has no evidence of sepsis on cultures, making steroids appropriate. Terlipressin is used for hepatorenal syndrome or variceal bleeding, not as primary therapy for alcoholic hepatitis. Pentoxifylline is an alternative with weaker evidence, not the first-line choice when steroids are not contraindicated.

• A. Pentoxifylline has weaker evidence than corticosteroids and is reserved for cases where steroids are contraindicated.
• C. Ursodeoxycholic acid is used in cholestatic liver diseases such as primary biliary cholangitis, not alcoholic hepatitis.
• D. Terlipressin is used for variceal haemorrhage or hepatorenal syndrome, not as treatment for severe alcoholic hepatitis.
• E. Albumin alone does not address the underlying inflammatory process and is not a substitute for steroid therapy here.

In suspected non-alcoholic fatty liver disease, NICE recommends using a non-invasive fibrosis scoring algorithm, such as the enhanced liver fibrosis (ELF) test, to assess the degree of liver fibrosis once steatosis has been confirmed. This stratifies patients into those needing routine primary care follow-up versus referral to secondary care hepatology for further assessment. Liver biopsy is invasive and reserved for cases where non-invasive tests suggest advanced fibrosis or the diagnosis is uncertain. Viral hepatitis serology is not indicated here as there is no risk factor or clinical suspicion pointing to viral hepatitis.

• A. Transjugular biopsy is a more invasive alternative to percutaneous biopsy used in coagulopathy or ascites, not a first-line test.
• B. Biopsy is invasive and not first-line; non-invasive fibrosis testing is performed first.
• D. There is no clinical indication for viral hepatitis screening in this patient with a clear risk factor profile for NAFLD.
• E. CT abdomen is not part of the standard NAFLD fibrosis assessment pathway and adds unnecessary radiation exposure.

Persistent hepatitis B surface antigen (HBsAg) beyond 6 months indicates chronic infection, and a positive hepatitis B e antigen (HBeAg) reflects active viral replication and high infectivity. The positive IgG (rather than IgM) anti-core antibody indicates that the infection is not acute, since IgM core antibody is the marker of recent or acute infection. Surface antibody negativity confirms that the patient has not cleared the virus or been vaccinated, which would show surface antibody positivity instead. The combination of HBsAg and HBeAg positivity with IgG core antibody is the classic pattern of chronic, highly infectious hepatitis B.

• B. Vaccination produces isolated surface antibody positivity without surface antigen or core antibody positivity.
• C. Low infectivity chronic infection is associated with e antigen negativity and e antibody positivity, not e antigen positivity as seen here.
• D. Past infection with immunity shows surface antibody positivity and surface antigen negativity, neither of which fits this pattern.
• E. Acute infection is associated with IgM anti-core antibody positivity, which is absent here; IgG positivity indicates a more established infection.

A positive hepatitis C antibody test indicates exposure to the virus at some point but does not distinguish between current infection, past infection that has cleared spontaneously, or successful prior treatment. Hepatitis C RNA testing by polymerase chain reaction (PCR) detects active viral replication and is required to confirm current infection before considering antiviral treatment. Liver function tests can be normal even with active hepatitis C infection and do not confirm viraemia. Core antigen testing is an alternative marker of active infection in some settings but RNA PCR remains the standard confirmatory test in UK practice.

• A. Repeating the antibody test does not distinguish current from past infection, since antibodies persist regardless of clearance.
• B. Core antigen testing can indicate active infection but is not the standard first-line confirmatory test used in UK clinical practice.
• C. Ultrasound assesses for structural liver disease but does not confirm whether active viral infection is present.
• D. Liver function tests can be normal in active hepatitis C infection and do not establish whether the virus is currently present.

This patient has jaundice, ascites, coagulopathy (raised INR) and hepatic encephalopathy (confusion, asterixis) on a background of chronic liver disease, which together define decompensated cirrhosis. These four features reflect loss of synthetic, excretory and detoxifying liver function and portal hypertension. The combination, rather than any single sign, is what clinches the diagnosis in a patient with known risk factors for chronic liver disease. Recognising this constellation prompts urgent assessment for precipitants (infection, gastrointestinal bleeding, drugs) and specialist referral.

• A. Withdrawal delirium does not account for jaundice, ascites or coagulopathy.
• B. Acute viral hepatitis would not typically cause ascites or the chronic stigmata described.
• C. Intoxication does not explain jaundice, ascites and coagulopathy.
• D. Wernicke's classically causes confusion, ataxia and ophthalmoplegia, not jaundice, ascites or asterixis.

Spontaneous bacterial peritonitis is diagnosed by an ascitic fluid polymorphonuclear neutrophil count of 250 cells/microlitre or more, which allows rapid empirical treatment while culture results are awaited. Ascitic culture is often negative in up to 40% of cases despite true infection, so a normal neutrophil count is more reliable for excluding SBP than a negative culture is for excluding it. The serum-ascites albumin gradient helps determine the cause of ascites (portal hypertensive versus other) but does not diagnose infection. Prompt diagnosis is essential because empirical antibiotics (such as intravenous cefotaxime) should be started as soon as SBP is suspected, without waiting for culture results.

• A. A raised amylase suggests pancreatic ascites or gut perforation, not SBP.
• B. Cytology is used to look for malignant cells, not bacterial infection.
• D. This gradient classifies the cause of ascites but does not indicate infection.
• E. Culture can take days to return and is frequently negative even in true SBP, so it is not the best diagnostic test.

Constipation is a common precipitant of hepatic encephalopathy because reduced gut transit increases ammonia production and absorption by colonic bacteria. Lactulose is first-line treatment: it acidifies the colonic lumen, converting ammonia to the poorly absorbed ammonium ion, and its laxative effect speeds the clearance of nitrogenous waste. The dose is titrated to produce 2-3 soft stools per day. If encephalopathy recurs despite lactulose, rifaximin is added as a bowel-selective antibiotic to reduce ammonia-producing gut flora.

• A. Neomycin is nephrotoxic and ototoxic with long-term use and is not first-line; rifaximin is preferred as second-line.
• C. Mannitol is used to reduce raised intracranial pressure, not hepatic encephalopathy from a metabolic precipitant.
• D. Flumazenil is reserved for benzodiazepine-induced encephalopathy, not a constipation-driven episode.
• E. Dexamethasone has no role in managing hepatic encephalopathy.

Spironolactone is the first-line diuretic for cirrhotic ascites because secondary hyperaldosteronism driven by portal hypertension is a major contributor to sodium and water retention. As an aldosterone antagonist, it counteracts this mechanism directly and is more effective than loop diuretics alone in mobilising ascitic fluid. Furosemide may be added if response to spironolactone alone is inadequate, but monotherapy with spironolactone is appropriate first-line therapy, alongside dietary sodium restriction. Serum potassium and renal function should be monitored, as spironolactone can cause hyperkalaemia.

• A. Amiloride is a weaker potassium-sparing option and is not first-line compared with spironolactone.
• C. Furosemide alone does not address the aldosterone-driven sodium retention and is usually added second, not used first-line.
• D. Thiazides are not used in cirrhotic ascites and are less effective with lower glomerular filtration rate.
• E. Indapamide is a thiazide-like diuretic with no established role in ascites management.

Hepatorenal syndrome is a functional renal failure occurring in advanced cirrhosis, driven by severe splanchnic vasodilatation that reduces effective circulating volume and triggers intense renal vasoconstriction. It is a diagnosis of exclusion, made after ruling out structural renal disease, nephrotoxic drugs, sepsis and hypovolaemia, and is supported by normal kidneys on ultrasound with low urinary sodium, reflecting avid renal sodium retention. Large-volume paracentesis without adequate albumin replacement is a recognised precipitant because it further reduces effective intravascular volume. Management involves albumin, terlipressin, and treating any precipitant, with liver transplantation as the definitive treatment.

• A. There is no history of recent contrast exposure.
• B. ATN typically shows high urinary sodium from tubular damage impairing sodium reabsorption, unlike the low urine sodium seen here.
• D. Glomerulonephritis would typically show haematuria or proteinuria on urinalysis, which is not described.
• E. Normal-sized kidneys without hydronephrosis exclude obstruction.

Patients with cirrhosis are at increased risk of hepatocellular carcinoma and should undergo surveillance with liver ultrasound and serum alpha-fetoprotein every 6 months, as recommended by NICE and international hepatology guidelines. This interval reflects the typical tumour doubling time and allows detection while lesions remain small enough for curative treatment such as resection, ablation or transplantation. CT and MRI are reserved for characterising lesions found on ultrasound, not as first-line surveillance tools, due to cost, radiation exposure and resource implications. Liver biopsy is not used for routine surveillance and carries unnecessary risk when imaging is diagnostic in most cases.

• A. MRI is more costly and resource-intensive and is used for further characterisation, not first-line surveillance.
• B. CT involves radiation and cost that make it unsuitable as a routine surveillance tool; it is used to characterise suspicious findings.
• D. Biopsy is invasive and not required for surveillance; it is reserved for indeterminate lesions.
• E. These liver function tests reflect synthetic function, not tumour detection, and are not surveillance tools for HCC.

The combination of severe, sharp post-defecatory pain, bright red bleeding, a history of constipation and a visible linear tear at the posterior midline is classic for an anal fissure. Fissures are usually caused by trauma from passing a hard stool, and the posterior midline is the most common site due to relatively poor blood supply there. Haemorrhoids typically cause painless bleeding unless thrombosed or prolapsed, and a perianal abscess presents with a painful, fluctuant, erythematous swelling rather than a visible tear, often with systemic features such as fever. Management of an acute fissure includes dietary fibre, adequate fluid intake, and topical glyceryl trinitrate or diltiazem to relax the internal anal sphincter and promote healing.

• A. A fistula typically presents with intermittent discharge from an external opening rather than an acute tear and sharp pain.
• B. An abscess presents as a painful fluctuant swelling with signs of infection, not a visible fissure.
• D. Haemorrhoids usually cause painless bleeding and are not seen as a linear skin tear.
• E. Rectal prolapse presents as protruding rectal tissue, not a linear mucocutaneous tear.