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Effect of food and anti-cholinergic drugs on the pattern of rectosigmoid contractions
1Centre for Human Nutrition, University of Sheffield, Northern General Hospital.
Abstract:
The colonic response to a meal is often used to test the effect of drugs on colonic motility, but this test is hindered by its inconsistency. This study has used multiple manometric sensors situated in the rectosigmoid region to investigate whether recording of the site and type of contraction offers a clear discrimination of the colonic response to a meal and the effect of drugs. Two studies were carried out on 16 healthy volunteers. Before the meal, rectosigmoid motility consisted mainly of isolated contractions occurring in a single manometric channel. The motility index increased in every subject after the meal (p < 0.05), but this increase entirely consisted of a massive increase in contractions occurring simultaneously in three or more manometric channels (multiple channel contractions), the number increasing from 9 per hour preprandially to 57 per hour (p < 0.01). There was a concomitant decrease in the number of the single channel contractions from 65 to 56 per hour. In a second study an infusion of an antispasmodic drug, mebeverine hydrochloride, into the sigmoid colon of healthy volunteers stopped the postprandial increase in the multiple channel contractions and prevented the significant rise in the motility index. The decrease in single channel contractions was unaffected. These results show that the colonic response to a meal consists of a change in the pattern of rectosigmoid contractions and suggest that multiple channel contractions may be a more sensitive indicator of the effect of a meal on the rectosigmoid colon than the motility index.
Insights
Meal responses in the rectosigmoid colon were studied using manometric sensors. Multiple channel contractions, not the motility index, accurately reflect meal effects and drug impacts on colonic motility.
Area of Science:
- Gastroenterology
- Colonic Motility
- Pharmacology
Background:
- Assessing drug effects on colonic motility using meal responses is inconsistent.
- Existing methods lack precision in differentiating colonic responses.
- Need for improved methods to analyze rectosigmoid colon activity.
Purpose of the Study:
- To investigate if recording contraction site and type discriminates colonic response to meals and drug effects.
- To evaluate multiple manometric sensors in the rectosigmoid region.
- To compare multiple channel contractions with the motility index.
Main Methods:
- Two studies conducted on 16 healthy volunteers.
- Rectosigmoid manometry recorded contractions before and after a meal.
- Infusion of mebeverine hydrochloride (antispasmodic) studied in the second phase.
Main Results:
- Postprandial colonic response characterized by a significant increase in multiple channel contractions (9 to 57/hour).
- Simultaneous decrease in single channel contractions observed (65 to 56/hour).
- Mebeverine hydrochloride inhibited postprandial increase in multiple channel contractions and prevented motility index rise.
Conclusions:
- Colonic response to meals involves a pattern shift in rectosigmoid contractions.
- Multiple channel contractions are a more sensitive indicator of meal effects on the rectosigmoid colon than the motility index.
- This method offers improved discrimination for drug effects on colonic motility.