Overview
Definition
A type of Inflammatory Bowel Disease (IBD) characterized by continuous mucosal and submucosal inflammation of the colon, always involving the rectum and extending proximally.
Epidemiology
Bimodal age distribution (peaks at 15-30 years and 50-70 years).
Etiology & Risk Factors
- Unknown exact cause; aberrant immune response to gut microbiota in susceptible hosts.
Clinical Symptoms
- Bloody diarrhea (cardinal symptom)
- Tenesmus (feeling of incomplete defecation)
- Crampy lower abdominal pain (often Left Lower Quadrant)
- Fever and weight loss in severe flares
Clinical Approach
Diagnosis
- Colonoscopy (Avoid during fulminant flares due to perforation risk): Continuous inflammation starting from rectum, loss of vascular pattern, friable mucosa, pseudopolyps
- Biopsy: Crypt abscesses, crypt branching, mucosal (superficial) inflammation ONLY (no granulomas)
- Fecal Calprotectin (marker of intestinal inflammation)
Management
- Mild/Moderate: 5-Aminosalicylates (5-ASA like Mesalamine) via oral or rectal route
- Severe Flare: IV Corticosteroids
- Refractory/Maintenance: Biologics (Infliximab, Vedolizumab), Janus kinase inhibitors (Tofacitinib)
- Surgery (Proctocolectomy with ileal pouch-anal anastomosis) is CURATIVE for UC
Complications
- Toxic Megacolon (life-threatening colonic dilation >6cm)
- Primary Sclerosing Cholangitis (PSC) - highly associated
- Significantly increased risk of colorectal cancer (requires annual surveillance colonoscopy after 8 years of disease)