A 26-year-old lactating mother presented with a 3-week history of abdominal pain, constipation, and vomiting. She denied any history of alcohol abuse or other gastrointestinal problems. Contrast-enhanced CT identified a small-bowel obstruction caused by a cecum cancer (Fig. 1A). Therefore, she underwent right hemicolectomy and ileocolic anastomosis. Post-operatively, she gradually developed drowsiness, fainting, and a rapid heart rate at 130 bpm. However, blood tests were all normal.