 Surgical treatment of deep endometriosis with bowel involvement is widely accepted to require complete excision of all endometriosis also when invading the bowel. In case of opening of the bowel a subsequent inflammatory reaction follows the surgery, as demonstrated by the increase in blood levels of C-reactive protein during the first post-operative week. Furthermore it increases the risk of post-operative bowel complications. In case of peritonitis the general surgeons use extensive lavage in order to decreases mortality, morbidity and post-operative adhesions formation, as demonstrated in animal models and clinically in patients with peritonitis. Considering the efficacy of extensive lavage for peritonitis and the inflammatory reaction as judged by the increased C-reactive protein CRP following full thickness deep endometriosis resection from the bowel, the study aims to evaluate, in women undergoing this procedure, the effect of extensive abdominal lavage on abdominal inflammation and post-operative bowel complications. 