Morphofunctional changes of hemomicrocirculation in the walls of the small intestine in acute strangulation intestinal obstruction and after its surgical elimination were studied experimentally on 60 mongrel dogs (weight 7-20 kg). It is demonstrated that main causes of complications in postoperative period were disorders of microcirculation in the walls of the small intestine and inflammation in the bringing part of the small intestine. On day 3 to 7 after elimination of strangulation intestinal obstruction hemomicrocirculation in tissues of bringing loop of small intestine did not meet the requirements for reparation after resection of necrotic part and creation of entero-enteroanastomosis. This is the cause of insufficiency of entero-enteroanastomosis in this time interval.