On the 4th day after the cesarean section, the woman developed fever, abdominal pain, and body temperature rose to 39°C. Pulse - 104/min. There was vomiting twice. The patient is inhibited, the tongue is dry, coated with a grayish coating. The stomach is swollen. Symptoms of peritoneal irritation are positive in all departments. Peristalsis is not heard. Gases do not escape. The bottom of the uterus is at the level of the navel. The uterus is painful on palpation. Purulent - bloody secretions, moderate. What is the most likely diagnosis?