Gastrointestinal food transport in relation to meal occurrence in rats

Food transport through gastrointestinal tract of rats is described by determining the location of methylenblue coloured standard food in the gastrointestinal tract at different intervals from the start of a meal on this coloured food. This transport was observed during first or second voluntary night meals after 2 hr or 24 hr of food deprivation. Food reaches the ileum 5–10 min after ingestion. This transport is independent of the presence of older food in the stomach. A second night meal starts while the stomach is relatively well filled (2 hr deprived rats) or very full (24 hr deprived rats). It was found that in a second night meal a sample of the food ingested during this meal is transported rapidly into the intestine. This sample is followed by food of preceding meal.