Piriformis syndrome usually does not cause diarrhea. Piriformis syndrome refers to the sciatic nerve being compressed in the region of the piriformis muscle; it is mainly manifested as pain in the buttocks on the affected side and radiating pain in the lower limbs; when the pain is particularly severe, the patient will have painful claudication, or even difficulty in walking, and it does not usually cause diarrhea. The causes of pyriformis syndrome include hip trauma, drug injection, acetabular fracture, etc.; the diagnosis is confirmed by physical examination as well as lumbar spine CT, electromyography, etc.; conservative treatments are mainly used, including massage to relieve the pain, physical therapy, etc.; when the pain is particularly severe, celecoxib, meloxicam and other medications can be used to alleviate the pain under the guidance of the doctor. Diarrhea is mainly manifested as an increase in the volume and frequency of defecation, stools are not shaped, etc.; the causes of diarrhea are different; according to the time of occurrence of diarrhea, it can be divided into acute diarrhea and chronic diarrhea. 1. Acute diarrhea: the possible causes are acute food poisoning, intestinal infections, acute ulcerative colitis, etc. Acute diarrhea is mostly caused by self-limiting infections, and if there is no obvious dehydration, it can be restored to normal after dietary treatment; severe cases need to be admitted to the hospital for rehydration and anti-infective treatment. 2. Chronic diarrhea: it may be caused by irritable bowel syndrome, ulcerative colitis, rectal cancer and other diseases; patients should go to the gastroenterology department of the hospital in a timely manner to find out the cause of the symptomatic treatment; such as diarrhea caused by irritable bowel syndrome, can be used under the guidance of the doctor to treat with pivoxyl bromide and other drugs. Patients with problems should go to the hospital in time and be treated under the guidance of a doctor.