Pneumatosis coli secondary to lactulose use masquerading as an acute abdomen

Pneumatosis coli (PC) is the radiological finding of gas within the wall of the colon. We present the case of a middle-aged woman admitted acutely with abdominal bloating and right-sided abdominal pain. Background included chronic back pain and constipation managed with long term methadone and high dose lactulose, respectively, and symptoms of abdominal bloating with increased flatulence. On abdominal examination there was right sided peritonism. Vital signs and bloods were normal. Computed tomography (CT) abdomen showed subserosal and submucosal air locules in the right colon, and a small volume of pneumoperitoneum. PC secondary to lactulose was suspected. Lactulose was ceased, and intravenous antibiotics given to suppress bacterial translocation. The patient symptomatically improved and was discharged on oral metronidazole. Her symptoms rapidly resolved and a CT scan at 6 weeks was normal. Clinically, the diagnosis of PC helped to prevent unnecessary acute surgery and allowed successful medical management to be initiated.