[A man with lower left abdominal pain].

A 57-year-old man presented with fever and lower left abdominal pain. The CT-scan showed thickening of the gallbladder wall with a fistula to the transverse colon, a laminated calcification in the descending colon and distended bowel loops. Resultantly, the patient was diagnosed with gallstone ileus. Sigmoidotomy was necessary to extract the stone and to prevent a blow-out of the colon.