A Colonoscopic Study of Aphthoid Ulcers of the Large Intestine

: Colonoscopic characteristics of aphthoid ulcers in amebiasis, Crohn's disease, and tuberculosis were evaluated. Multiple aphthoid ulcers were featured in 14 out of 15 cases of amebiasis, 7 out of 74 cases of Crohn's disease, and 5 out of 24 cases of tuberculosis. Aphthoid ulcers of amebiasis were often confined to the rectum and lower sigmoid colon, being characterized by marginal elevation and erythema. Crohn's aphthoid ulcers lacked the red halo in all but one case. No verrucous elevations were observed. The intervening mucosa appeared intact in all cases. Aphthoid ulcers of intestinal tuberculosis were oval or lozenge-shaped. They were surrounded by a marginal red halo in 4 cases (80%), however, the red halos found in tuberculosis patients were milder than those of patients with amebiasis. Aphthoid ulcers of Crohn's disease and tuberculosis showed a tendency to be arranged in a specific direction. Crohn's ulcers were arranged in a longitudinal fashion, whereas tuberculous ulcers were arranged in a circular fashion. Ulcers of amebiasis were arranged entirely at random. Biopsy from aphthoid ulcers of amebiasis showed parasites in 64%, whereas cytological studies were positive in 93% of cases.