A noninvasive radionuclide assessment of colonic transit of nondigestible solids in man

A reproducible, noninvasive, scintigraphic, large-intestinal-transit-time quantification technique was developed that provides low radiation dose, unlimited information content and high patient acceptance. The proposed technique, called the Large Intestinal Transit (Encapsulated), or LITE, uses a total of 100 microcuries of In-111 encapsulated in ten 2-centimeter long nondigestible capsules which are ingested after a 6 hour fast. 250 microcuries of Tc-99m sulfur colloid was given to outline the gastrointestinal tract. Images were acquired at 4 hour intervals for 72 hours (except overnight) or until all capsules were excreted. Ten subjects consumed a standardized diet 2 days prior to and during imaging, in order to control dietetic variables. The LITE technique provided a simple, quantitative measure of the variables associated with colonic function. Mouth-to-anus transit was measured along with detailed transit times in each of the colon's six anatomical segments: ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon and recto-sigmoid colon. The radiation absorbed dose to the large intestine, for the LITE technique, was found to be over 50% lower than that associated with previously existing methods of large intestinal transit time measurement. The LITE method represents a major advancement in that it requires no invasive medical procedures. Finally, the LITE technique holds tremendous clinical promise for diagnosing segmental colonic disorders and studying therapeutic pharmaceutical efficacy