Intraluminal pressure in the sigmoid colon. I. Method and results in normal subjects

A modified method for measurement of pressure activity in the sigmoid colon is presented, using open-ended tubes and measurement of pressure activity for 30 minutes after intravenous administration of 0.5 mg of neostigmine. The motility index in 12 normal persons was found to have median 597 with a range of 125-1169. Variation among persons exceeded the day-to-day variation significantly. Error in reading the curves was negligible.