The topography of ileoanal reservoirs in relation to evacuation patterns and clinical functions.

The clinical outcome following ileoanal pouch operations vary greatly. To understand the underlying mechanism 15 S-shaped reservoirs and one J-shaped were studied by defecography (evacuation pouchography). Efficient evacuation was noticed when the reservoir was placed deep in the pelvis with the outlet of the pouch on a level with the 5th sacral vertebra or coccyx, and when the efferent limb was short (less than or equal to 7 cm) and straight. When the pouch was placed higher up in the pelvis and when the efferent limb was long and angulated, evacuation was impaired. Patients with efficient evacuation all had excellent clinical functions with few (less than or equal to bowel movements in 24 hours and no leakage, but when the evacuation was impaired there was a tendency towards more frequent stooling and leakage.