Changes in colonic motility during the development of chronic large bowel obstruction

Abstract

The effect of chronic progressive distal large bowel obstruction on colonic motility was studied in six mini-pigs. Motility was detected in vivo during the development of obstruction with chronically implanted Ag/AgCl electrodes using an impedance technique. When the obstruction was complete the segments of bowel were resected and spontaneous contractile activity and response to cholinergic stimulation were studied in an organ bath. Any hypermotility resulting from obstruction was shortlived and a gradual state of hypomotility supervened proximal to the obstruction. Decompression of the bowel did not result in the immediate return of motility and the resected bowel was unresponsive to carbachol. These results suggest that spontaneous resolution of large bowel obstruction is unlikely and that motility disturbances are unlikely to be a cause of anastomotic dehiscence.

Microsomal Prostaglandin E Synthase-1 Plays a Critical Role in Long-term Motility Dysfunction after Bowel Obstruction

“…This transient motility change may result from neuronal mechanisms similar to the physiological peristalsis reflex where food bolus (or luminal accumulation in obstruction) stimulates mechano-receptors in the gut wall to initiate neuronal regulations of ascending excitation and descending inhibition 33 – 35 . Motor activity in the obstructed bowel soon (in hours) becomes compromised with marked suppression of phasic contractions and muscle tone 18 , 33 , 36 , 37 . Gut motility function continues to be suppressed as long as obstruction is present.…”