Effect of intragastric or intraduodenal administration of a polymeric diet on gallbladder motility, small-bowel transit time, and hormone release

Objective: During postpyloric tube feeding, GI intolerance is observed more frequently than during prepyloric feeding, possibly by evoking a stronger GI response. Methods: We investigated the effect of intragastric and intraduodenal administration of a polymeric diet (125 kcal/h) on gallbladder motility (by ultrasonography), duodeno-cecal transit time (by lactulose H2 breath test), and GI hormone release (including cholecystokinin, pancreatic polypeptide, and gastrin). Six healthy subjects (two male, four female; mean age 22 yr, range 18–27 yr) were studied on two separate occasions in random order during 6 h of continuous administration of the diet through either the gastric or duodenal port of a two-lumen tube. Results: Intraduodenal feeding resulted in a more rapid contraction of the gallbladder, from 32 ± 4 to 23 ± 4 cm3 at 10 min (p < 0.05), reaching a minimum of 6 ± 1 cm3, in contrast to intragastric feeding (31 ± 4 to 19 ± 3 cm3 at 60 min, p < 0.05; minimum 14 ± 1 cm3). The gallbladder remained contracted during the 6-h study period during both intraduodenal and intragastric feeding. Small-bowel transit time was significantly accelerated during intraduodenal compared with intragastric feeding (51 ± 12 vs 81 ± 9 min; p= 0.003). Plasma cholecystokinin secretion was significantly (p < 0.05) increased during intraduodenal compared with intragastric feeding (848 ± 107 vs 279 ± 89 pmol · L−1· 360 min). The same was true for pancreatic polypeptide secretion. However, gastrin release was significantly (p < 0.05) higher during intragastric feeding. Conclusions: Intraduodenal feeding elicited a stronger GI response than intragastric feeding, as demonstrated by accelerated small-bowel transit time, more rapid and stronger gallbladder contractions, and increased cholecystokinin and pancreatic polypeptide release. Gastrin release, on the other hand, was stronger during intragastric feeding.