Ulcerative colitis
Ulcerative colitis is a chronic immune-mediated disease of continuous mucosal inflammation that begins in the rectum and extends proximally through the colon, presenting with bloody diarrhea and tenesmus and confirmed by colonoscopy with biopsy. Treatment is stepped by extent and severity from 5-aminosalicylates through corticosteroids, immunomodulators, and biologics, with acute severe disease requiring IV corticosteroids and medical or surgical rescue, and colectomy remains curative.
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What this article covers
- Overview
Definition: a chronic immune-mediated inflammatory bowel disease causing continuous mucosal and submucosal inflammation beginning in the rectum and extending proximally through a variable length of colon, without skip areas.
- Epidemiology
Bimodal age distribution: an initial peak in the second to fourth decades, with a smaller second peak in the seventh and eighth decades.
- Risk factors
First-degree relative with inflammatory bowel disease: the leading identifiable risk factor.
- Pathophysiology
Genetic susceptibility plus dysregulated mucosal immunity: an abnormal immune response to gut microbiota in a genetically predisposed host.
- Clinical features
Bloody diarrhea: the hallmark symptom; proctitis alone can instead present as constipation with frequent small-volume bloody stools.
- Differential diagnosis
Crohn disease: transmural, skip-lesion disease, often with rectal sparing, granulomas, fistulas, strictures, and pain more prominent than bleeding (crohn disease).
- Diagnosis
Established by colonoscopy with biopsy showing continuous friable mucosa from the rectum proximally, with crypt abscesses and no granulomas, after excluding infection: severity is graded as mild…
- Management
Match therapy to extent and severity after excluding infection: step through 5-aminosalicylates, corticosteroids, immunomodulators, and biologics or small molecules, targeting mucosal healing, not symptom relief alone.
- Complications
Toxic megacolon: colonic dilation with systemic toxicity, precipitated by opioids, anticholinergics, hypokalemia, or barium enema; managed with hospitalization, infection treatment, and urgent colorectal surgery consultation.
- Prognosis
Colectomy is curative of the colonic disease: removing the colon and rectum eliminates flare risk and colorectal cancer arising from residual colon, a cure not available in Crohn disease.
- Prevention
Colorectal cancer surveillance colonoscopy: begin 8 years after diagnosis for disease proximal to the rectum, then repeat every 1 to 3 years; ulcerative proctitis alone needs no surveillance.
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