Eating a meal on the large may be caused by physiological factors, may also be caused by pathological factors. 1. Physiological factors: usually the increase in gastrointestinal peristalsis after the patient has eaten will lead to the urge to have a bowel movement, thus promoting the emptying and digestion of food in the stomach and small intestine. Some patients have developed the habit of defecation after meals. If the regularity of defecation, such as the frequency, shape and color of defecation are normal, without any discomfort or weight loss, this is usually a normal physiological phenomenon. 2. Pathological factors: generally mainly caused by gastrointestinal dysfunction and inflammatory bowel disease. For example, patients with irritable bowel syndrome may have symptoms such as abdominal pain, abdominal distension, and changes in stool characteristics; inflammatory bowel disease is mainly manifested as diarrhea, abdominal pain, and even pus and blood stools, which varies in severity and is easily repeated. There may be other reasons for having large bowel movements after eating, and patients are advised to actively seek medical attention to clarify the cause of the disease and then undergo regular treatment.