A 67-year-old man initially presented with intermittent dysphagia to both solids and liquids, along with nonbloody diarrhea. He has a temperature of 100 °F. He has unintentionally lost 10 lb in the past 2 months. He is a former smoker without past gastrointestinal (GI) illness. He has no family history of GI cancer or inflammatory bowel disease. An initial colonoscopy showed diverticulosis and moderate signs of inflammation.

During a hospitalization for abdominal pain, early satiety, and intolerance to oral intake, he underwent CT of the abdomen, which revealed thickening and inflammatory stranding of the distal colon. Skip lesions and mucosal nodularity ("cobblestoning") were found. Biopsies obtained from the distal colon demonstrated chronic active mucosal inflammation, with the presence of severe granulation tissue and granulomas. Perianal manifestations included tags, fissures, fistulae, abscesses, and purulent discharge.