Intestinal complications

Complications of inflammatory bowel disease (IBD)

Pathogenetically, the development of specific complications depends on the depth of inflammatory damage to the intestinal wall. The prolonged course of any inflammatory bowel disease (with a history exceeding ten years) is considered a significant risk factor for the development of colorectal cancer. The spectrum of pathologies is strictly differentiated depending on the form of the disease.

In ulcerative colitis (UC), inflammation is acute and accompanied by extensive erosive and ulcerative destruction of the colonic mucosa. This leads to the development of life-threatening conditions:

• Profuse intestinal bleeding.
• Toxic dilation of the colon (toxic megacolon). It occurs because the inflammatory infiltrate destroys the intramural nerve plexuses.
• Perforation of the intestinal wall, which predictably results in severe sepsis.

Specific complications of Crohn's disease (CD)

Unlike ulcerative colitis, the pathogenesis in Crohn's disease is driven by the transmural nature of the inflammation: the process originates in the submucosa and gradually penetrates the entire thickness of the wall. This creates the substrate for structural-spatial disorders and purulent-destructive processes (intra-abdominal and pararectal abscesses, penetrations, inter-intestinal, and perianal fistulas).

Main complications of CD:

1. Strictures (narrowing). Thickening of the wall leads to lumen narrowing. They occur in 30–50% of patients and are localized in the small intestine, colon, or rectum. The consequence of strictures is intestinal obstruction (most often partial; complete obstruction is rare).
2. Bleeding. Although generally more characteristic of UC, massive bleeding occurs in Crohn's disease due to the formation of deep cleft-like ulcers penetrating deep into the submucosa (especially with colonic involvement).
3. Perforations. Due to transmural infiltration, single or multiple perforations may occur. Typical localization is on the side opposite to the mesenteric border of the intestine.

Amebic granuloma (Ameboma)

Ameboma is a rare complication that forms during the prolonged course of amebiasis without adequate specific treatment. Pathogenetically, it represents an inflammatory perifocal infiltrate forming in the intestinal wall directly around the ulcer defect.

• Localization and clinical presentation: The cecum and ascending colon are most frequently affected. Palpation (usually in the right iliac region) reveals a tender tumor-like mass with a firm, elastic consistency.
• Diagnostics: Based on medical history, clinical picture, and colonoscopy data. Direct and indisputable proof is the detection of amebae in stool analysis.
• Risks: Addition of secondary purulent flora leads to the breakdown of the infiltrate. This is followed by intestinal perforation and the development of fecal peritonitis. Also, a large granuloma can provoke obturation intestinal obstruction.
• Treatment: Uncomplicated forms are treated conservatively. Emergency surgery is indicated if therapy is ineffective, purulent complications develop, or signs of intestinal obstruction appear.

Class and exam questions

What else to study on this topic

• Pathogenesis of the destruction of intramural nerve plexuses in UC
• Mechanisms of cleft-like ulcer formation in Crohn's disease
• Purulent-destructive processes: penetrations and abscesses
• Colorectal cancer as an outcome of long-standing IBD
• Morphological picture of chronic productive inflammation in ameboma

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.