Measurement of intestinal progression of a meal and its residues in normal subjects and patients with functional diarrhoea by a dual isotope technique.

A new double isotopic method was used to measure the gastrointestinal progression of a meal in nine healthy subjects and seven patients with functional diarrhoea. 51 Chromium chloride (colonic marker) was ingested eight hours before the beginning of the scintigraphic study so that it was by then located in the colon at that time. A second marker, 99m Technetium sulphur colloid labelled the meal. Scintigraphic images were taken before and after the meal for two hours, detecting simultaneously the two isotopes. In the 51 Cr window right colon was localised and intracolonic propulsion was studied; and in the 99m Tc window gastric emptying and colon filling of the meal marker was quantified. A propulsive gastrocolic reflex was evidenced in five of the seven patients with functional diarrhoea but in none of the normal subjects. Unabsorbed residues of the meal are propelled rapidly in the ileocaecal region. Small intestinal transit of the meal marker was twice as rapid in patients with functional diarrhoea as in normal subjects.