Female patient was urgently admitted to the surgical department. The patient underwent a general clinical examination, abdominal and chest radiography, endoscopy, CT of the abdominal organs, consultations with related specialists. To establish a definitive diagnosis and determine the course of treatment, a laparotomy was performed, involving debridement and drainage of the abdominal cavity. As the condition continued to progress, a subtotal colectomy with colostomy was performed. X-ray of the chest, abdominal organs, and fibrogastroduodenoscopy revealed no pathology. CT scan revealed signs of bilateral pneumonia and ascites. During fibrocolonoscopy, a diagnosis was made: Crohn’s disease of the sigmoid colon. Due to the development of peritonitis, laparotomy, sanitation and drainage of the abdominal cavity were performed. The condition was worsening. Relaparotomy, subtotal colectomy, and colostomy were performed. On the third day after relaparotomy, the condition sharply worsened and death occurred. The case we studied emphasizes that when assessing the nature of acute surgical pathology of the abdominal cavity, it is necessary to remember Crohn’s disease, especially when combined with damage to other systems. When diagnosing this disease, it is necessary to use all possibilities, but the determining factor for making a diagnosis is histological examination. Surgical treatment of Crohn’s disease should include all drugs in accordance with clinical protocols, with the use of surgical treatment if complications develop.