In general, the pain in the left lower abdomen relieved after defecation is considered to be caused by physiological factors such as constipation and pathologic factors such as Crohn’s disease and intestinal tuberculosis. 1. Physiological factors: constipation, cold and other causes of abdominal distension, eating too much or eating spicy food, can cause pain in the lower left abdomen, usually after defecation can be relieved. 2. Pathologic factors: (1) Intestinal tuberculosis: it is a chronic specific infection caused by Mycobacterium tuberculosis invading the intestines. The intestinal contents containing Mycobacterium tuberculosis stay in the ileocecal region for a long time, such as constipation, etc., which can increase the chances of infection of the local mucosa, thus leading to intestinal tuberculosis. Most of the pain is in the right lower abdomen, but it can also be in the left lower abdomen, periumbilical region and the whole abdomen with dull or sharp pain, which is aggravated after eating and relieved after defecation. (2) Acute gastroenteritis: acute inflammation of the gastrointestinal tract caused by dietary impurity, etc., mainly manifested as abdominal pain, abdominal distension, nausea, vomiting and fever, myalgia and other symptoms. (3) Crohn’s disease: a chronic non-specific inflammation of the intestinal tract, most commonly found in the end of the ileum and the adjacent colon, the main symptoms are abdominal pain, diarrhea, weight loss and so on. There are many other causes of left lower abdominal pain relieved after defecation, such as intestinal polyps, etc. It is recommended to seek timely medical attention in order to clarify the diagnosis and carry out targeted treatment.