The reasons for this are as follows: 1. The gastrocolic reflex, also known as the gastrocolic reflex, is generally caused by the stomach filling after eating, which reflexively causes an increase in the movement of the colon, a phenomenon known as the gastrocolic reflex. Generally, people with strong gastrocolonic reflexes are prone to have a sense of bowel movement after meals or when eating; 2. Some patients may be suffering from irritable bowel syndrome, which is a group of syndromes with continuous or intermittent episodes of abdominal pain, abdominal discomfort, changes in bowel habits, diarrhea or constipation. Some patients may also develop irritable bowel syndrome due to mental stress; some patients with irritable bowel syndrome have diarrhea as soon as they eat. These conditions belong to a functional disease, most people belong to this category, you can eat pivetonium bromide, calcium antagonists, mainly to inhibit the spasm of the smooth muscle of the intestine, in order to relieve the above discomfort; 3, some patients have organic lesions, so if there are changes in the stool habits, or to do a colonoscopy, to exclude the intestinal tract has no organic lesions.