The discovery of calculi in the intestine may be of considerable importance in the diagnosis of chronic constipation or of partial ileus. Intestinal calculi may be found in any portion of the colon, where stagnation of faecal matter occurs for a more or less prolonged period. Favourite sites are the appendix, caecum, ascending colon, the lower part of the sigmoid, colon and the rectal ampulla. Two types of calculi are recognised; the so-called coproliths and true calcareous concretions. The case described below belongs to the second group. Examination of the intestine by the use of contrast media will reveal the calculi in the form of sharply defined oval filling defects. The fact that these defects move freely within the bowel helps to differentiate them from tumours. A 33-year-old female patient was admitted to the Department of Internal Medicine under suspicion of chronic ileus. She had always been in good health until four years before when she had an attack of alleged biliary colic. Cholecystography,...