THE ANAL-SPHINCTER IN IDIOPATHIC MEGARECTUM - EFFECTS OF MANUAL DISIMPACTION UNDER GENERAL ANESTHETIC

PURPOSE: This study was designed to investigate the function and morph ology of anal sphincters in patients with an idiopathic megarectum. ME THODS: A total of 17 patients were studied by anal endosonography and manometry when not impacted. Fourteen had previously been manually dis impacted under general anesthetic, and three had not. RESULTS: Nine of 14 patients in the former group, but none of the latter group, had di sruption of one or both anal sphincter muscles on endosonography. Endo sonographic changes were characteristic of those identified previously in patients following anal dilation. Low anal resting pressure, indic ative of internal sphincter dysfunction, was found in a substantial pr oportion of patients with either an endosonographically intact or disr upted internal anal sphincter. Voluntary contraction increment, a refl ection of external sphincter function, was normal in all patients. CON CLUSION: Manual disimpaction under general anesthetic appears to be as sociated with iatrogenic structural injury to the anal sphincters. In some patients, this may contribute to sphincter weakness. This damage may contribute to the incontinence experienced by patients with a dila ted rectum.