A 7-week-old baby presented to a district general hospital with a history of pallor, lethargy, vomiting and high pitched cry. She had vomited three times at home. It was reported that the last vomitus had a greenish tinge to it. In hospital, she had a non-bilious vomit. There was no history of fever, constipation or diarrhoea. Her birth history and medical history were unremarkable. She was noted to be pale, lethargic and quiet on examination. Her vital signs were unremarkable. She had a soft scaphoid abdomen on examination. No masses were palpable. Investigations for sepsis were done and antibiotics started. Results of all the investigations were normal apart from mildly raised blood glucose and neutrophilia. Later on she passed a small amount of blood per rectum. Examination revealed a palpable mass in the epigastrium. An abdominal x-ray was suggestive of intestinal obstruction. Intussusception was confirmed on ultrasound. The intussusception was successfully reduced following surgery.