Visual Diagnosis: An 11-Month-Old With Nausea, Vomiting, and an Abdominal Mass

Presentation

An 11-month-old girl presents to the emergency department (ED) with 12 episodes of nonbilious, nonbloody vomiting and decreased activity for the past 24 hours. Her medical history and family history are notable for the following. She was born at term via an uncomplicated, induced vaginal delivery. There is a paternal history of diabetes. The patient’s half-sister, who has phenylketonuria, was ill with nausea without vomiting 2 days before the patient’s presentation. Yesterday the patient was seen in the ED for nausea and 5 bouts of emesis. She was discharged after receiving one dose of ondansetron and could tolerate clear liquids by mouth. She now returns to the ED for continued vomiting.

On physical examination the patient’s temperature is 37.9°C, heart rate is 114 beats per minute, respiratory rate is 30 breaths per minute, blood pressure is 105/65 mm Hg, and oxygen saturation is 98% in room air. She is comfortable and sleeping but awakens when physically examined. Mucous membranes are slightly dry, and her posterior oropharynx is erythematous. Cardiac auscultation reveals normal S1 and S2 heart sounds without a murmur. She has good peripheral perfusion and normal capillary refill. Her lungs are clear to auscultation. She has no abdominal scars, and bowel sounds are normal. Her abdomen is soft and nontender, and no masses are palpable. The spleen and liver are not enlarged. Abdominal radiography reveals a normal bowel gas pattern.

The patient is admitted for intravenous hydration. Despite treatment with ondansetron, frequent vomiting persists. During her second hospital night, she has several large bowel movements that contain blood and mucus. Her …