Acetylcholinesterase distribution and refractory constipation - a new criterion for diagnosis and management.

To describe manifestations of acetylcholinesterase (AchE) activity in the bowel of patients presenting with refractory constipation and correlate them with outcome, rectal biopsy specimens (RBS) from 165 patients who presented with refractory constipation between 1988 and 1999 were examined. Age at biopsy ranged from 4 days to 17 years; 45 subjects were excluded because they satisfied diagnostic criteria for Hirschsprung's disease, intestinal neuronal dysplasia, or hypoganglionosis. Thirty-five autopsy subjects were used as controls. All RBS were compared and AchE activity was assessed in the lamina propria (LP), muscularis mucosae (MM), and around the submucosal vessels (V). Variations in AchE distribution were classified as grade I (no AchE-positive nerve fibers in the LP or MM), grade II (some positive fibers in the LP or MM), grade III (moderate positive fibers in the LP or MM), grade IV (many positive fibers in the LP, MM, or V), or grade V (fibrillar, foamy, or amorphous staining for AchE). All grade I (11/120) and V (12/120) subjects achieved normal bowel control with laxatives alone and all grade II subjects (58/120) did with laxatives and enemas. Grade III subjects (34/120) required addition of cisapride. All grade IV subjects (5/120) were unresponsive to conservative management and 4/5 were found to have a megarectum, which was treated surgically. AchE distribution correlated well with eventual outcome and requirement for surgery. AchE distribution could also be used to classify bowel motility disorders, and we suggest the term AchE-positive disease be used to describe them.