Hidden pain in the left abdomen and farting all the time may be caused by functional dyspepsia, constipation, colitis, sigmoid colon tumor and other reasons. 1. Indigestion: usually often eat hard to digest food, greasy food can lead to gastrointestinal dysfunction, causing indigestion, resulting in a vague pain in the left lower abdomen, always farting. 2. Constipation: an unbalanced diet or low activity can lead to constipation, which can cause the stool to remain in the intestines for a long period of time, and then react to the gas production, and the feces will remain in the intestines, so it will cause hidden pain in the lower left abdomen and farting all the time. You can actively exercise such as running, swimming, etc. to enhance the metabolic function of the body. It can enhance the peristalsis of the gastrointestinal tract and promote better absorption of food. 3. Colitis: Inflammatory reaction is triggered by the infection of pathogenic bacteria in the colon, and the inflammatory factor stimulates the intestinal smooth muscle to cause intestinal inflammation and spasm, which can lead to vague pain in the left abdomen, farting all the time, and can be accompanied by symptoms such as increased frequency of bowel movements. 4. Sigmoid colon tumor: the tumor of sigmoid colon can cause vague pain in the left lower abdomen, farting all the time, often accompanied by bloody stools, weight loss and other symptoms because of the invasive effect of the tumor. Left abdominal pain, always farting, if the adjustment of diet, can not be relieved, it is recommended to consult a doctor in time, according to the cause of the appropriate treatment program, so as not to delay the condition.