The incidences of appendicectomy, hysterectomy and ovarian surgery have been compared in 145 patients with irritable bowel syndrome (IBS) and 63 patients with ulcerative colitis (UC). The appendicectomy rate in IBS patients (34.5%) was more than 4 times greater than that in UC patients (7.9%). Likewise, 55.2% of 87 women with IBS underwent hysterectomy or ovarian surgery compared with only 18.5% of 27 women with UC. This increased incidence of abdominal surgery in patients with IBS is probably part of a pattern of chronic illness behaviour; doctors should be aware of this problem when dealing with these cases.