Number Of High-amplitude Propagated Contractions Research Articles

Fermentation of starch stimulates propagated contractions in the human colon

In healthy humans, up to 30 g of daily ingested starch escape small intestinal digestion, and are fermented in the colon. This physiological starch malabsorption could modify colonic motility through metabolites such as short-chain fatty acids produced by fermentation. Ten healthy volunteers swallowed a probe, consisting of an infusion catheter, six perfused catheters and a balloon connected to a barostat. On two consecutive days colonic motility was recorded in fasting subjects in the basal state (1 h), and then during (3 h), and after (2 h) the intracolonic infusion of 750 mL of isoosmotic and isovolumetric solutions containing sodium chloride with or without 15 g wheat starch. We determined (i) the volume of hydrogen and methane exhaled in breath, (ii) a global motility index and the number of high amplitude propagated contractions (HAPCs), and (iii) the mean balloon volume, reflecting the tonic motor activity. [median (IQR)] Compared to the basal period, colonic infusion of starch or saline did not modify the colonic motility index and tone. However, the number of HAPCs was significantly higher during and after infusion of starch than of saline [4.5 (2.75-6.5) vs 0.96 (0-2.66)/5 h, starch vs saline respectively; P = 0.011]. In healthy humans, colonic fermentation of a physiological malabsorbed amount of starch has no effect on the tonic and phasic colonic motor activities, but produces a significant increase in the number of HAPCs. This may participate in the physiological propulsion of colonic contents.

How Do Antegrade Enemas Work? Colonic Motility in Response to Administration of Normal Saline Solution Into the Proximal Colon

The aim of the study was to evaluate the colonic motor response to the administration of normal saline into the proximal colon. Pediatric patients undergoing colonic manometry received a saline infusion (10-20 mL/kg) in 10 minutes through the central lumen of a catheter placed into the proximal colon. We compared the number of high-amplitude propagated contractions (HAPCs), motility index, frequency and propagation of other phasic contractions in the 20 minutes before and after normal saline infusion, meal ingestion, and bisacodyl administration. Thirteen patients, mean age 9.4 ± 5.8 years, received the saline infusion (3 in the cecum, 8 in the hepatic flexure, and 2 in the transverse colon). In the first 20 minutes after saline infusion, the number of contractions (P = 0.005), distance of propagation of contractions (P = 0.007), frequency of contractions (P = 0.009), and motility index (P = 0.003) were significantly higher compared with baseline. Mean amplitude and number of HAPCs were not significantly different from baseline. Motility parameters after saline and after ingestion of a meal did not differ. All of the measured motility variables significantly increased after bisacodyl stimulation. Bisacodyl increased the motility index and HAPCs more than either saline infusion (P = 0.002) or meal intake (P < 0.001). Infusion of saline into the proximal colon is associated with an increase in colonic motility; however, at the volume and rate used in the present study it does not consistently stimulate HAPCs.