[Perforation in Crohn's ileitis and its consequences in the natural history of disease. 2. Consequences of perforation in the peritoneal cavity: diffuse septic peritonitis, abscesses, external and internal fistulas].

Perforation of Crohn's ileitis occurring in the peritoneal cavity is always free perforation, but it causes usually a localized peritonitis, i.e. an abscess, and only in rare cases a diffuse septic peritonitis for the reasons expounded in the Part 1. Diffuse septic peritonitis has the common features of all perforative peritonitis; its surgical treatment must be ileocolic resection, simple suture of perforation being a serious mistake. Abscesses develop: as regards the ileum, about 30-45 cm from the ileo-caecal valve; as regards the abdominal cavity, in the right iliac fossa or in the pelvis, at a site where the ileum, weighed down by its chronic inflammation, rests. These abscesses have a wall like that of all abscesses, with no specific crohnian features. On operation, if technical considerations so require, part of the abscess wall may be left in place with no fear of recurrences or fistulas. Nowadays, most abscesses of the right iliac fossa are opened surgically; an enterocutaneous fistula follows. Most abscesses of the pelvis still open spontaneously into a hollow organ (sigma-rectum, urinary bladder), and rarely into the vagina or onto the perineum after penetrating through the levator any muscle and causing suppuration of the ischiorectal fossa.