Ulcerative Colitis

Ulcerative colitis is a relapsing and remitting inflammatory disorder of the colonic mucosa. It may affect just the rectum (proctitis) or extend proximally to involve  part  or the entire colon (pancolitis) without small bowel involvement. However, in 10–15% of patients it may involve the terminal ileum/ ileocecal valve due to “backwash ileitis.”

Cause:   Likely multifactorial etiology involving interplay of environmental factors, genetic susceptibility, and immune system dysregulation.  

Incidence:   19.2/100,000 person years in North America. Bimodal age of onset, most patients diagnosed between 15–30, and 10–15% after age 50. More UC patients tend to be former smokers than Crohn’s.

Symptoms  
Gradual onset of diarrhea ± blood and mucus. Crampy abdominal discomfort is common; bowel frequency is related to severity of disease (see below). Systemic symptoms are common during attacks, e.g., fever, malaise, anorexia, weight loss. Urgency and tenesmus occur with rectal disease. Proctitis may occasionally present as obstipation or constipation associated with urgency/tenesmus.

Signs  
May be none: In acute, severe UC: Fever, tachycardia, and a tender, distended abdomen.   Extraintestinal signs   Clubbing, aphthous oral ulcers, erythema nodosum, pyoderma gangrenosum, conjunctivitis, episcleritis, iritis, large joint arthritis, sacroiliitis, ankylosing spondylitis, fatty liver, PSC, cholangiocarcinoma and, very rarely, renal stones, osteomalacia, nutritional deficiencies, and systemic amyloidosis.

Tests  
Blood:   CBC, erythrocyte sedimentation rate (ESR), c-reactive protein