Hypokalaemic hyperchloraemic metabolic acidosis and vesical stone complicating appendicovesical fistulae

Two patients with appendicovesical fistulae are described. Both presented with gastrointestinal and urinary symptoms. Biochemical examination showed hypokalaemic hyperchloraemic metabolic acidosis; radiographic investigations showed a vesical stone and a communication between the bladder and the bowel. The findings at operation suggested that the fistulae may have arisen as complications of previous appendicitis. The diagnosis of appendicovesical fistulae may be difficult but should be considered in the presence of hypokalaemic hyperchloraemic metabolic acidosis and vesical stones.