Calculous cholecystitis severe enough to result in pyloric outlet obst
ruction is a rare occurrence. Impaction of a large calculus in the duo
denum or stomach as a consequence of fistula formation is usually diag
nosed on upper gastrointestinal series. Computed tomography is uncommo
nly used to diagnose this condition and was diagnostic in our patient.
(C) Elsevier Science inc., 1998.