METALLICmercury, generally regarded as inert, is known to stimulate the formation of granulomatous lesions.1 We have recently treated a patient in whom intestinal obstruction was caused by mercury granulomas. It is clear from our experience and from a review of the literature that rupture of the mercury-filled balloon fixed to the end of a long intestinal tube may lead to serious complications. In this communication, we list practices which we now follow in such cases. Report of a Case A 68-year-old man was admitted to the hospital with symptoms and physical signs of intestinal obstruction. The diagnosis was confirmed by roentgenograms. Three years before, the patient had had sigmoid colectomy for chronic volvulus. Two months later, he had mechanical intestinal obstruction, which, during a 48-hour trial, failed to respond to intestinal decompression with a Miller-Abbott tube. Abdominal exploration was required for enterolysis. Two enterotomies had to be done to decompress