Pouch dynamics--a simple test of ileo-anal pouch evacuation.

A simple technique for quantifying ileo-anal pouch evacuation has been used to compare patients with good pouch function and fully spontaneous defaecation (n = 10) to patients with a symptomatic disorder of pouch evacuation (n = 10), usually due to a pouch-anal stricture (n = 7). Pouch emptying was significantly less efficient in those with disordered evacuation (median 54% evacuated) than in those with good function (median 98% evacuated, p = 0.02) and significantly slower (median 22.4 sec vs 5.2 sec to evacuate 75% of instilled barium, p less than 0.02) even when of comparable efficiency. Testing of four further patients with high stool frequency but neither stenosis nor symptomatic difficulty with evacuation excluded a significant disorder of evacuation in three but identified inefficient emptying in the fourth. This test may prove useful in the investigation of patients with poor pouch function of uncertain origin.