COMPARISON OF SIMULTANEOUS RECORDINGS OF HUMAN COLONIC CONTRACTIONS BY MANOMETRY AND A BAROSTAT

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 to ne of the colon by means of combined multilumen manometry and a barost atic balloon that was infinitely compliant, conformed to the colon's i nner wall, and was clamped at a constant 'operating' pressure througho ut the study. A computer program separated indices of the colon's moto r function detected by the barostat: a baseline volume and phasic volu me events. The barostat detects on average 70% more phasic pressure ev ents than manometric sideholes located 2 cm proximal to 7 cm distal to the balloon. Manometry becomes less sensitive than the barostat when the colonic diameter exceeds 5.6 cm. The barostat detects on average 9 0% of all propagated and non-propagated (>30 mmHg) manometric peaks. T he baseline volume changes significantly after the ingestion of a 1000 -kcal meal, consistent with an increment in colonic tone, undetected b y manometry. A combined barostat-manometry assembly appears to be pref erable to manometry alone in the intraluminal evaluation of human colo nic pressure activity and tone.