Compulsive lying on the back is a position in which the patient lies on his back with his legs flexed to relieve tension on the abdominal muscles in order to relieve the pain of the disease. It is commonly seen in acute peritonitis. Secondary peritonitis Acute perforation and rupture of intra-abdominal organs: the most common cause of acute secondary peritonitis. Perforation of cavernous organs often occurs suddenly due to progression of ulcerative or gangrenous lesions, e.g., acute appendicitis, peptic ulcer, acute cholecystitis, typhoid ulcer, gastric or colon cancer, ulcerative colitis, ulcerative intestinal tuberculosis, amoebic bowel with diverticulitis. The differential diagnosis of forced supine position: 1. forcedstandingposition: During activity, due to the sudden onset of pain in the precordial region, the patient immediately stops in place and often presses his hand to the precordial area, and only after relief and improvement, leaves the original position. 2.Forced prone position (compulsivelyingontheface): prone position can make the muscles of the spine and back relaxed, seen in spinal diseases. 3, forced lateral recumbency (compulsivelyingontheside): pleural disease more lying to the affected side, in order to reduce pain or coughing, and help the healthy side of compensatory breathing, seen in one side of pleurisy or a large number of pleural effusion. 4, forced sitting position (sitting breathing, orthopnea): sitting position, hands on the knees or support the side of the bed, in order to make the diaphragm fall to increase lung volume and lower extremity back to reduce the heart burden, seen in cardiac and pulmonary insufficiency. 5, forced squatting (compulsivesquatting): short distance walking or other activities due to the feeling of breathing out of difficulty and palpitations and take the squatting distance position or knee-chest position to relieve symptoms, seen in cyanotic congenital heart disease. It is often accompanied by flexion of the legs to reduce abdominal muscle tension.