Crohn's disease of the colon. IV. Clinical features of Crohn's (ileo) colitis.

Using accepted diagnostic criteria we have selected, for study, 160 patients with Crohn's disease involving the colon. There is a remarkable discrepancy between the clinical diagnosis prior to or at the time of initial admission to this hospital and the diagnosis following definitive investigation and observation of the progression of disease. The peak age incidence occurred in the second decade. The colitis group showed a greater percentage of patients over 30 years of age. Although histopathology was not obtained in all patients, there appeared to be sparing of the ascending colon in a small percentage (9 percent) of patients with ileocolitis. Comparison of the clinical features of granulomatous disease limited to the colon and granulomatous ileocolitis shows a significantly greater incidence of extraintestinal symptoms and overt bleeding in the former. Nausea, vomiting, subacute obstruction, abdominal mass and internal fistulas were substantially more common in ileocolitis but the difference was not statistically significant. In this series retroperitoneal abscess did not occur in patients with disease localized to the colon. In the 10 patients with ileocolitis who developed an abscess, however, the site of fistula was the colon in four patients. In one of these, the abscess was left-sided.