We present a case of acute postoperative abdominal pain after proctosigmoidectomy and colorectal anastomosis that was treated by bilateral continuous quadratus lumborum block. The block was performed in the lateral position under ultrasound guidance with a 15-mL bolus of 0.5% bupivacaine injected anterior to the quadratus lumborum muscle followed by bilateral catheter placement. Each catheter received a continuous infusion of 0.1% bupivacaine at 8 mL/h and an on-demand bolus 5 mL every 30 minutes. Sensory level was confirmed by insensitivity to cold from T7 through T12. The block was devoid of hemodynamic side effects or motor weakness. This case demonstrates that bilateral continuous quadratus lumborum catheters can provide extended postoperative pain control.