Prognostic factors of recurrent external intestinal fistulas after extraperitoneal closing them were studied in 74 patients operated on in the Sverdlovsk region clinical hospital N1 in 1990-2004. There were no lethal outcomes. Good results were noted in 40 out of 74 (54.05%) patients. Postoperative complications developed in 34 (45.95%) patients, including 21 (28.38%) recurrent intestinal fistulas. Using the methods of mathematical analysis it was found that the recurrent intestinal fistulas resulted from persisting inflammatory alterations in the tissues of the peritoneal and intestinal walls and also from appearing due to operation mechanical injuries of patency of the intestine canal in the places of suturing the fistulas or the initial ones - in the abducent parts of the intestine. The indications and contraindications are proposed concerning the using, rational technical means of extraperitoneal closing the external intestinal fistulas.