Influence of Rectal Decompression on Abdominal Symptoms and Anorectal Physiology following Colonoscopy in Healthy Adults

Background. Postcolonoscopy abdominal discomfort and bloating are common. The aim of this study was to evaluate whether rectal decompression improved distension-induced abdominal symptoms and influenced anorectal physiology. Methods. In 15 healthy subjects, rectal distension was achieved by direct air inflation into the rectum by colonoscopy. Placement of rectal and sham tube was then performed in each subject on a separate occasion. The anorectal parameters and distension-induced abdominal symptoms were recorded. Results. Anorectal parameters were similar between placements of rectal tube and sham tube except for greater rectal compliance with rectal tube than with sham tube (P < 0.05). Abdominal pain and bloating were significantly reduced by rectal tube and sham tube at 1 minute (both P < 0.05) and 3 minutes (both P < 0.05). After placement of rectal tube, abdominal pain at 3 minutes correlated positively with first sensation (r = 0.53, P = 0.04), and bloating at 3 minutes also correlated positively with urge sensation (r = 0.55, P = 0.03). Conclusions. Rectal decompression with either rectal or sham tube improved distension-induced abdominal symptoms. Our study indicates that the mechanisms that improved abdominal symptoms by rectal decompression might be mediated by a central pathway instead of a peripheral mechanism.