The reason for back pain and inability to defecate is as follows: 1. When the patient is in a squatting position during defecation, the back of the waist will be in a tight state, which will lead to an increase in the burden on the muscles of the waist, making it easy for the patient’s waist to become painful. 2. Back pain and inability to defecate are typical symptoms of constipation. 3. The presence of ureteral stones can also cause difficulty in the discharge of stool and lumbar pain, and when the stones move to the connection between the ureter and the kidney, the pain in the lumbar area will increase, which will also affect the discharge of stool. Patients with this condition need to have their lumbar muscles examined promptly, avoid stones, and eat more fiber-rich foods to promote food elimination.