An endoscopic method to study the relationship between bowel habit and motility of the ascending and sigmoid colon.

Endoscopic retrograde bowel insertion (ERBI), a new method, offers rapid access to the entire colon for pressure sensors. The authors measured the pressure of both the ascending colon and the sigmoid colon and related them to the bowel habits of the subjects. The following groups were studied: control subjects, patients with diarrhea-dominant irritable bowel syndrome, patients with constipation-dominant irritable bowel syndrome, and patients with right-sided diverticular disease of the colon. In patients with irritable bowel syndrome with diarrhea or constipation, colonic motility indices (CMIs) showed a so-called "paradoxical motility" pattern. In patients with right-sided diverticular disease, the CMI was higher in the ascending colon than in the sigmoid colon. The pattern of CMIs for diverticular disease and irritable bowel syndrome varied inversely in the ascending colon and in the sigmoid colon with diarrhea and constipation. These results suggest that the mechanisms of altered bowel habits in patients with these diseases are quite different.