Fig. 1.

An 11-year-old male patient diagnosed with Philadelphia chromosome-positive ALL failed to pass stools for 157 hours before an abdominal CT was undertaken. Initial imaging showed massive colonic dilatation and fecal impaction consistent with ACPO, with the maximum diameter of the ascending colon measuring approximately 6.7 cm (A). Four hours after imaging, the patient was started on subcutaneous neostigmine, which resulted in stool passage 1 hour later. The patient received 1 more infusion for rapid amelioration of symptoms. Follow-up imaging taken 7 days later showed improvement in both colonic dilatation and fecal loading with a decrease in the maximum diameter of the ascending colon to 4.8 cm (B).