Description 

A 24-year-old man with autism spectrum disorder presented to accident and emergency complaining of a 1-week history of abdominal pain and diarrhoea. He had a history of chronic constipation with multiple previous admissions stretching 4 years back. On examination, he had a tender, distended abdomen with quiet bowel sounds. His CT scan on admission (figure 1) showed a dilated (up to 18 cm) rectum and sigmoid colon filled with faeces. The patient was managed conservatively with oral laxatives and regular enemas. However, the patient refused the enemas and was maintained on oral laxatives. Two days later, the patient complained of worsening abdominal pain. On examination, he had a peritonitic abdomen and reduced consciousness level. Biochemical investigations revealed worsening renal function and that the patient was now acidotic. A chest X-ray revealed free air beneath the diaphragm. A repeat CT scan …