Extensive jejunal and colonic intussusception is a rare type of intestinal impaction. The aim of the work is to present a therapeutic-diagnostic algorithm for an atypical clinical picture of a rare form of intussusception of intestines (II) in a child of 4 months. A clinical observation of extensive ileocolic intussusception was carried out in a 4-months-old child admitted to the clinic to exclude craniocerebral trauma 34 hours after falling from a height of 1 m. Results. The main reason for seeking medical help was repeated vomiting and lethargy in a child, occurred one day after the fall. The identification of bloody discharge from the anus was a reason for excluding II. The consecutive use of ultrasound, colonoscopy made it possible to confirm the diagnosis, diagnose irreversible circulatory disorders in the invaginate and determine the indications for laparotomy. The absence of peritonitis allowed performing a resection of the necrotic area of the intestine with the application of intestinal anastomosis after desintussusception. Factors provoking the disease were the introduction of a new nutritional formula in the diet and the “lead point” in the form of a Meckel›s diverticulum Conclusion. The symptom of “blood in the stool”, even in the absence of a typical clinical picture, requires the exclusion of II. The diagnostic arsenal (ultrasound, colonoscopy, laparoscopy) in a specialized hospital with rare forms of II allows short-term diagnosing and choosing a rational surgical tactic. The absence of peritonitis during resection of the necrotic area of the intestine makes it possible to perform the anastomosis.