Synchronous obstruction of large and small bowel may be missed radiologically and even at laparotomy when the small-bowel obstruction masks the large-bowel obstruction. The five patients reported illustrate this problem. It can only be diagnosed in certain patients by barium enema after small-bowel obstruction has been shown on plain radiographs. In four patients, this was especially applicable: patients with known or suspected abdominopelvic malignancy with loops of small bowel and pelvic colon involved by either tumor spread or irradiation fibrosis after treatment. One patient had ischemic strictures manifesting rather unusually in this manner.