[Diagnostic pitfalls of complicated colonic diverticulosis].
Irritable bowel syndrome and (or) non complicated diverticulosis, associated with fever, could simulate diverticulitis. Cancer of the sigmoid colon appears the main differential diagnosis, when diverticulitis is associated with an atypical or complete colonic stenosis on opaque enema, with a vesicoenteric fistula or with a peritonitis due to a colonic perforation. Even at laparotomy, a pseudotumoral diverticulitis cannot easily be differentiated from a colonic carcinoma. Acute diverticulitis of the caecum or ascending colon is usually mistaken for acute appendicitis. When massive and life-threatening bleeding occurs, the diverticular origin is difficult to assess. Bleeding due to peptic ulcer disease and thermometric ulceration being precluded, arteriography performed on emergency is necessary to differentiate between diverticular bleeding and angiodysplasia.