Thirty patients with acute pseudo-obstruction of the large bowel are presented, and the aetiology and diagnosis of this recognized clinical entity are described. Emergency barium enema examination is recommended in patients with symptoms and signs of large bowel obstruction. When no mechanical blockage is found a diagnosis of pseudo-obstruction can be made. The management of pseudo-obstruction is conservative, with nasogastic suction, intravenous fluids and the treatment of any associated condition such as cardiac failure and inflammatory conditions. The indications for surgery in pseudo-obstruction are discussed.