The objectives of the study presented here were to evaluate the role of faecal stasis in the development of acute appendicitis. Inquiries about bowel habits were made of 188 patients admitted to this Department of Surgery with a clinical diagnosis of acute appendicitis, and of 188 healthy volunteers without known gastrointestinal disease, matched for age and sex. The results show that the number of bowel actions per week were significantly lower in the group of patients with acute appendicitis. Furthermore, the patients with a gangrenous and perforated appendix found at operation had significantly fewer bowel actions per week than those with phlegmonous appendicitis. These findings support the hypothesis of the importance of the obstruction of the appendix lumen in the development of acute appendicitis.