RIGHT AND LEFT COLONIC TRANSIT AFTER EATING ASSESSED BY A DUAL ISOTOPIC TECHNIQUE IN HEALTHY HUMANS

Propulsion of colonic contents after eating in the whole colon was studied in 15 volunteers by scintigraphy with injection of 111In-diethylenetriaminepentaacetic acid and 99mTc-sulfur colloid into the colon through a nasogastric tube. The radionuclide was injected into the cecoascending colon (n = 7), the hepatic flexure (n = 6), the splenic flexure (n = 9), and the descending colon (n = 4). Changes of activity in the regions distal from and proximal to the injection points were determined before and after a 1000-kcal meal. Isotopic movements were also analyzed when a simultaneous injection of the two markers in the right and left parts of the colon was achieved (n = 11). During fasting, no significant change of activity was seen. After eating, radioactivity injected into the cecoascending and the hepatic flexure was transferred distally (P < 0.01 and P = 0.07); radioactivity injected into the splenic flexure was transferred both distally (P = 0.07) and proximally (P < 0.02); and no significant change of activity was seen proximally from or distally to the descending colon. Both antegrade and retrograde isotopic movements increased after eating (P < 0.01), but the number of antegrade movements was significantly greater (P < 0.05). This study confirms the colonic propulsive effect of eating and shows that this response is different in the right and left parts of the colon. © 1992.