Of 99 patients with 117 gastrointestinal bezoars, 69 had undergone previous surgery, the most common operation being bilateral truncal vagotomy with pyloroplasty (55 patients). An excessive intake of vegetable fibre was found in 38 patients and poor mastication in 27. Thirty bezoars presented with gastric symptoms and patients had endoscopy as the diagnostic technique; 87 caused symptoms of intestinal obstruction with the diagnosis made by plain abdominal radiography. Medical treatment by enzymic or endoscopic fragmentation was used for 17 of 30 gastric bezoars; surgery was required in the remainder. Intestinal bezoars causing obstruction can be fragmented and 'milked' to the caecum. The stomach should be explored for associated gastric bezoars.