Diagnosis and differential diagnosis of colonic diverticulitis.

A patient over 40 years of age who complains of lower abdominal pain, constipation or diarrhea or both, and increased flatulence should be suspected of having diverticulosis. When pain becomes more severe and persistent, diverticulitis must be considered. Diagnosis depends on roentgen demonstration of the presence of diverticula. Sigmoidoscopy and barium enema study are essential to exclude coexisting disease but in diverticulitis may need to be postponed until severe local and systemic signs of inflammation have subsided. A number of diseases can simulate diverticulitis, and differential diagnosis may present considerable difficulty. Irritable colon syndrome and acute appendicitis may be indistinguishable clinically from diverticulitis. Differentiation from carcinoma is usually not difficult, but exclusion of coexistent carcinoma may be impossible except by resection. Ulcerative colitis is also easily distinguished except when, rarely, it coexists. Crohn's disease of the colon is less easily differentiated, especially in patients over 40, in whom the two diseases often coexist. Other colonic diseases, such as ischemic colitis, and pelvic inflammatory diseases usually show characteristic features which make them readily distinguishable from diverticulitis.