A 16-year-old Chinese male patient, who had a past medical history of hyperventilation complicated by carpopedal spasms, presented to the emergency department with constipation of five days' duration, colicky abdominal pain, lethargy, weakness and body aches. He was still able to pass flatus, and did not complain of vomiting, fever, chills or rigors. On examination, the abdomen was soft and non-tender. Digital rectal examination was unremarkable, as was the full blood count, except for a raised total white blood cell count of 16.6 × 10 9 /L. Renal and liver function tests and urinalysis were also unremarkable. The patient was hospitalised for further investigation of constipation. During his hospital stay, abdominal radiography was performed (Fig. 1). He subsequently desaturated acutely, and computed tomography (CT) was performed (Fig. 2)