Flow Of Intestinal Contents Research Articles

Current aspects of intestinal motility and transport.

The fact that interactions exist between intestinal motility and epithelial transport ist intuitively obvious but difficult to define experimentally. Direction, velocity and rate of flow of intestinal contents depend on the absolute and relative frequency and on the force of stationary and propagated lumen-obliterating (ring) contractions. The motility pattern differs between the fasting and the postprandial state and so do the magnitude and patterns of flow. The fed pattern of motility is primarily modulated by the chemical composition of ingested meals. Changes in epithelial transport are associated with changes in motility and vice versa; these changes are initiated by physical forces or by neuroendocrine reflex activation. Stomach, small intestine and colon are coordinated by antegrade stimulatory and retrograde inhibitory mechanisms which secure completeness of nutrient absorption and facilitate elimination of food residues. Motility and epithelial transport are controlled by intramural and central neural stimulation and by hormones acting systemically, locally (paracrine action), or as neuromodulators.

Loop ileostomy. Techniques and indications.

The records of 15 patients whose surgical treatment involved the construction of a loop ileostomy were reviewed. Indications for loop ileostomy include the necessity to protect multiple or complicated anastomoses, the protection of ileorectal anastomoses in patients with inflammatory disease, and the necessity of diverting the flow of intestinal contents in patients with fulminant inflammatory bowel disease. The technique of constructing and taking down a loop ileostomy is described.

Relationship of motility to flow of contents in the human small intestine

To measure simultaneously motility and flow of intestinal contents, a multilumen polyvinyl tube was passed by mouth in 10 healthy volunteers. Motility was recorded at five sites, spanning 100 cm of tube, to allow recognition of migrating motor complexes during fasting and during their disruption by food. Loci were designated as jejunal, ileal, and terminal ileal, as judged by length of tube in the intestine and by fluoroscopy. Flow of intestinal contents was measured by indicator (phenolsulfonphthalein) dilution over a 20-cm segment; flow was related to motility at the perfusion site. A liquid test meal of 400 ml and 600 kcal, containing polyethylene glycol 4000, was eaten after 6 h of fasting. During fasting, flow of intestinal contents was inter-mittent at all levels and varied with the presence of or absence of the activity front (“phase 3” of the migrating motor complex). The activity-front periods contributed 50% of total flow, but occupied less than one-third of the total recording time. Flow corrected for time was significantly greater with the presence of activity front than with phases 1 or 2 of the migrating motor complex (p < 0.001). In addition, of 45 increments in flow of greater than 0.75 ml · min−1, the majority (82%) were associated with an activity front. The flow rate increased promptly after a meal and fluctuated markedly during the postprandial period in most studies. By the time migrating motor complex had returned, more than 90% of meal marker (polyethylene glycol) was accounted for in intestinal aspirates. In contrast, only 56%–73% of marker was recovered postprandially in those studies in which the migrating motor complex had not returned by the time the study was terminated. Thus, flow of intestinal content is largely intermittent during fasting, peaks of flow being associated with passage of the activity front of the migrating motor complex; on the other hand, half the fasting flow is unassociated with the activity front. Reappearance of the migrating motor complex at any level after a liquid test meal signals clearing of the liquid meal from the more proximal intestine.

Gastric Hypersecretion After Formation of Small Bowel Conduits

As a preliminary step in studying the effect on gastric acid secretion in dogs following biliary diversion through isolated intestinal conduits, blind-ended intestinal conduits were constructed and the biliary channel was left undisturbed at this time. The results were surprising in that a significant absolute increase in gastric acid secretion occurred in all dogs, within the range of 65-286%, by merely disconnecting a segment of small bowel from the mainstream of flow of intestinal contents. This effect may be due to the "intestinal phase of gastric secretion hormone" and may in itself provide a partial explanation for the well-documented increase in gastric acid production caused by the Exalto-Mann-Williamson procedure and by choledochoenterostomy utilizing a Roux loop.