Comparison of simultaneous recordings of human colonic contractions by manometry and a barostat

Abstract Our hypothesis was that manometry in the colon was less sensitive than the electronic barostat in detection of colonic contractions. In ten healthy volunteers, we have characterised the pressure activity and tone of the colon by means of combined multilumen manometry and a barostatic balloon that was infinitely compliant, conformed to the colon's inner wall, and was clamped at a constant ‘operating’ pressure throughout the study. A computer program separated indices of the colon's motor function detected by the barostat: a baseline volume and phasic volume events. The barostat detects on average 70% more phasic pressure events than manometric sideholes located 2 em proximal to 7 cm distal to the balloon. Manometry becomes less sensitive than the barostat when the colonic diameter exceeds 5.6 em. The barostat detects on average 90% of all propagated and non‐propagated (>30 mmHg) manometric peaks. The baseline volume changes significantly after the ingestion of a 1000‐kcal meal, consistent with an increment in colonic tone, undetected by manometry. A combined barostat—manometry assembly appears to be preferable to manometry alone in the intraluminal evaluation of human colonic pressure activity and tone.