On the 3rd day after the artificial abortion the woman was hospitalized into the gynecological department in a severe condition with signs of intoxication, abdominal pain, and purulent discharge from the vagina. Objectively, the patient’s condition is severe, her body temperature is 38.8°C, pulse is 100/min., blood pressure is 110/70 mm Hg, the uterus is soft, the uterine fundus is located at the level of the navel, there are positive signs of peritoneal irritation. What is the most likely diagnosis?