Recurrent pneumoperitoneum after hysterectomy.

In most instances, patients with an acute abdomen and pneumoperitoneum have a perforated hollow viscus as the underlying cause. Clinicians must not forget, however, some of the less common causes of free air in the abdomen. We describe pneumoperitoneum from a vaginoperitoneal fistula, developing after hysterectomy, well known to gynecologists, but rarely noted in the medical literature.