Transient gas-filled appendix developing during excretory urography

Gas-filled appendix is well recognized in association with appendicitis, and in acute abdominal conditions associated with bowel distension. 3 patients who developed gas-filled appendix in the course of excretory urography are reported. The phenomenom is thought to result from the reported property of ionic contrast materials to produce anticholinesterase activity and histamine release, either or both of which could produce increased bowel tone and consequent displacement of cecal gas into the appendix.