Ulcerative Colitis

ULCERATIVE COLITIS 37A

A 43-year-old man presents to the urgent care clinic with bloody diarrhea. He has had five or six stools per day for the past 7 days associated with crampy abdominal pain and a feeling of incomplete emptying of his bowels. He has had similar episodes in the past, although this one is particularly severe. Physical examination shows a diffusely tender abdomen and blood on digital rectal examination. His blood hemoglobin is 8.3 g/dL. Sigmoidoscopy reveals a friable colonic mucosa, and biopsies show inflammation confined to the mucosal surface.

What are the salient features of this patient’s problem? How do you think through his problem?

Salient features: Bloody diarrhea; abdominal pain and tenesmus; abdominal tenderness; blood on rectal examination; anemia; friable colonic mucosa; colonic mucosal surface, not transmural, inflammation on biopsy

How to think through: What is the differential diagnosis here? (Infectious colitis caused by Escherichia coli O157:H7, Shigella, Campylobacter, or Salmonella spp.; inflammatory bowel disease [IBD]; ischemic colitis; colon cancer; and diverticulosis.) Although the friable mucosa in ischemic colitis can resemble IBD, this patient is atypically young for ischemic colitis and lacks atherosclerotic risk factors. The tempo does not fit colon cancer. Diverticular bleeding is usually painless. What medical history helps distinguish IBD from infection? (His prior similar episodes favor the diagnosis of IBD.) What extraintestinal symptoms and signs increase suspicion for IBD? (Fever, uveitis, arthritis, ankylosing spondylitis, erythema nodosum, pyoderma gangrenosum, sclerosing cholangitis, thromboembolism.) What studies should be obtained? (A complete blood count [CBC] to assess for anemia; serum electrolytes and creatinine to assess for diarrhea-related dehydration and hypokalemia; stool culture to exclude infection. Without a risk factor [e.g., travel to an endemic region or men who have sex with men], stool ova and parasite testing is low yield. Fecal leukocyte testing is not useful because of poor specificity. Sigmoidoscopy is diagnostic and easier and safer than pancolonoscopy in acute colitis.) How should his IBD be treated? (For mild disease, rectal or oral 5-ASA derivatives (e.g., sulfasalazine); for severe disease, corticosteroids, mercaptopurine, azathioprine, or infliximab.)