Hidden pain in the left lower abdomen after eating may be related to physiological factors such as improper diet, or pathological factors such as ulcerative colitis and intestinal spasm. 1. Improper diet: when eating too much greasy, spicy and stimulating, raw and cold food, due to the gastrointestinal mucosal irritation or indigestion, the patient may experience symptoms such as hidden pain in the lower left abdomen, diarrhea, abdominal distension and so on. 2. Ulcerative colitis: it is a chronic non-specific intestinal inflammatory disease of undetermined etiology, and patients may have recurrent diarrhea, mucopurulent blood stools, vague pain in the left lower abdomen or lower abdomen and other symptoms. 3. Intestinal spasm: If you have a vague pain in the lower left abdomen after eating, it may be caused by intestinal spasm. It may be due to intestinal spasms triggered by food irritation, causing the hidden pain. There are many other causes of hidden pain in the left upper abdomen after meals, and it is recommended to consult a doctor in time for targeted treatment.