A 66 year old white woman developed an incomplete small-bowel obstruction after 3 years of CAPD with lactate containing solutions. There were six episodes of peritonitis. The bowel obstruction was not due to a "sclerosing obstructive" (encapsulating) peritonitis but to a diffuse sclerosis of the serosal membranes extending into the muscle layers of the small and large bowels ("mural fibrosis"). This picture may be just one other expression of a spectrum of structural changes resulting from long-term chronic irritation of the abdominal cavity.