Gulp: Adventures on the Alimentary Canal

by Mary Roach

At a university hospital in Nancy, a sixty-nine-year-old man arrived at the Services des Maladies de l’Appareil Digestif (French for “Gastroenterology Department”). With the current set to 4, the doctor began a simple polypectomy. Eight seconds into it, an explosion was heard. “The patient jerked upwards off the endoscopy table,” reads the case report, and the colonoscope was “completely ejected” (French for “launched from the rectum like a torpedo”). What was strange was that the Frenchman had followed his colonoscopy prep instructions to the letter. The culprit, in this case, had been the laxative. The staff had prescribed a solution of mannitol, a sugar alcohol similar to sorbitol, the likely laxative agent in prunes. Though the man’s colon contained no fecal matter, it still contained bacteria, hungry bacteria that feasted on the mannitol and produced