The inter-observer reliability is very low at clinical examination of parastomal hernia

Parastomal hernia in patients with a permanent colostomy is common. The aim of this study was to evaluate the reliability of the diagnosis based on clinical examination and to compare this examination with the result of a specially designed questionnaire and computerised tomography (CT) scan. Forty-one patients operated upon with an abdominoperineal resection due to rectal cancer at three hospitals between 1996 and 2002 were included. At minimum of 4 years after the operation, they underwent clinical examination by two or three independent surgeons, answered a colostomy questionnaire and were offered a CT scan of the abdominal wall. At Hospital I, 17 patients were examined by three surgeons, with inter-observer kappa values between 0.35 and 0.64. At Hospital II, 13 patients were examined by three surgeons, the kappa values ranged between 0.29 and 0.43. At Hospital III, 11 patients were examined by two surgeons, with kappa value of 0.73. The kappa value between CT scan and the colostomy questionnaire was 0.45. The inter-observer reliability was low, indicating that parastomal hernia is difficult to diagnose by patient history and clinical examination. Some herniae may not be detected by CT scan, and the correlation to patient-reported complaints is low. A more sensitive radiological method to detect parastomal hernia is needed.