130 patients with Crohn’s disease were colonoscopied in a multicenter trial. The obtained data were analyzed with respect to gathering information on the inflammation pattern, as well as on the importance and prognostic value of special lesions in Crohn’s colitis. In 52 patients a second endoscopy was performed at the end of the 2-year study period. Ulcerations and aphthous lesions were the most common lesions, followed by pseudopolyps, cobblestone lesions and stenosis. In general, there was an increasing, distal gradient in the frequency of severe lesions. Patients with Crohn’s colitis alone had more signs of inflammation than patients with additional involvement of the small intestine. A segmental pattern was the most common form of inflammation. The group of patients (14%) with a continuous pattern did not deviate from the whole collective in clinical activity. In patients with previous resections, inflammation near the anastomosis was accompanied more often than not by stenosis. Patients with ulcerations had a rather short time since confirmation of the diagnosis. Cobblestone lesions and pseudopolyps correlated with short symptomatology. During the follow-up of the study, patients taking steroids or a combination with prednisolone and sulfasalazine seem to have better results than those under placebo or sulfasalazine alone, as regards the more severe sym