Utility of the instant (unprepared) enema in Crohn's colitis.

Thirty-seven instant (unprepared) barium enemas in 30 patients with proven Crohn's colitis were reviewed. Plain films in 28 indicated that confluence or discontinuity of the colitis did not substantially alter the pattern of faecal residue. In only one patient was residue found overlying active mucosal disease. Aphthoid ulceration was demonstrated in 27%. In five (13%) examinations the colitis was granular and indistinguishable from ulcerative colitis. In 26/37 (70%) typical stigmata of Crohn's colitis were present. There was no complication or clinical deterioration after the instant enema. The instant enema was found to be comparable to a prepared examination for the diagnosis of advanced Crohn's disease, though less accurate for demonstrating early changes.