For prophylaxis of severe signs of the postcolectomy and diarrheal syndromes, as well as the secondary anal incontinence syndrome, occurring after extended radical operation--colectomy, extremely low anterior rectal resection, mucosectomy, performed for severe diffuse nontumoral colon diseases, a pelvic small-intestinal anatomic-functional reservoir construction of a new type, which includes a small-intestinal reservoir with ileoendoanal anastomosis, was elaborated. In accordance to data on roentgenological control of the contrast small-intestinal transit the laws of its abdominal localization and peculiarities of morphological reconstruction in late terms after the operation were established. Application of a new type construction elaborated in 26 patients have permitted to reduce the occurrence rate for postoperative complications and the disease recurrences essentially, as well as to improve functional results of treatment.