Duodenojejunal motility after oral and enteral nutrition in humans: a comparative study

Small bowel motility during enteral nutrition (EN) remains poorly known. Our aim was to compare, in six healthy volunteers, the duodenojejunal motor patterns after a 750-kcal meal either ingested or infused intraduodenally at two different infusion rates: 2 kcal/min for 6 hours (6-hour EN) or 1 kcal/min for 12 hours (12-hour EN).

In each volunteer, the three manometric studies were carried out in a random order with an interval of > or = 1 week between each recording. Number of phase III (PIIIs), their characteristics, number of waves (NW), and area under the curve (AUC) were determined.

PIIIs were interrupted by each type of nutrition in every volunteer. In five of six during 6-hour EN and in six of six during 12-hour EN, the first PIII returned before the end of EN. The mean duration of the fed pattern was similar in the three studies. During the interruption of PIIIs after oral meal, duodenojejunal motility was characterized by uninterrupted random contractions. By contrast, in four of six during the 6-hour EN and in five of six during 12-hour EN, it was organized as regular short bursts of contractions separated by motor quiescence. In all studies during the disruption of PIIIs, NW and AUC values decreased progressively with time and were higher at the jejunum level than in the duodenum (p < .001). However, at each level of recording, NW and AUC values were similar in the three types of feeding. After the return of PIIIs, the number, duration, and propagation velocity of PIIIs, NW, and AUC values were similar in the three studies.

EN interrupts PIIIs, but, in most cases, PIIIs reappear before the end of EN. During the interruption of PIIIs, the organization of the contractions is qualitatively different from the fed pattern observed after oral feeding. For the same caloric value of the meal, the quantitative duodenojejunal motor response is not affected by the infusion rate, and the more important jejunal, rather than duodenal motor response found after an oral meal, is observed during EN. During EN, after the return of PIIIs, despite the persistence of a nutrient infusion into the duodenum, the small bowel motor patterns are not qualitatively or quantitatively different from those recorded in fasting subjects.