Pain in the small of the stomach after eating is not excluded from enteritis, especially in patients with a previous history of ulcerative colitis. The onset of abdominal pain after eating, or after eating irritating foods, can also be accompanied by diarrhea and, in severe cases, nausea and vomiting. Patients with occupational lesions of the intestinal tract may also experience abdominal pain, as well as significant abnormalities in bowel movements and changes in bowel patterns. Simple abdominal infections and pelvic infections may also present with abdominal pain and fever, which can be further confirmed by ultrasonography. For infectious diseases of the abdominal cavity, anti-infective treatment should be actively chosen; for inflammatory diseases of the intestinal tract, attention should be paid to dietary modifications, and symptomatic treatments such as anti-inflammatory and immune modulation can be given.