Clinical meaning
Ulcerative colitis (UC) is a chronic inflammatory bowel disease that affects ONLY the colon and rectum. The inflammation is continuous (no skip lesions) and starts at the rectum, extending proximally in a continuous pattern. Unlike Crohn's disease, UC involves only the mucosa and submucosa (superficial layers) of the bowel wall. The hallmark symptom is bloody diarrhea with mucus, often 10-20 or more stools per day during flares. Patients experience urgency, tenesmus (painful straining), and cramping abdominal pain typically in the left lower quadrant. Serious complications include toxic megacolon (acute colonic dilation with systemic toxicity), perforation, and significantly increased risk of colorectal cancer after 8-10 years of disease. UC follows a relapsing-remitting pattern with periods of flare and remission. Unlike Crohn's disease, UC is curable with total colectomy (surgical removal of the entire colon).
Exam relevance
Risk factors: - Family history of inflammatory bowel disease - Age 15-30 years (peak onset period) - Ashkenazi Jewish descent - Smoking cessation (paradoxically increases risk - smoking is protective in UC) - NSAID use can trigger flares - Stress and emotional distress worsen symptoms