Stomach pain sometimes and sometimes not may be caused by improper diet, Helicobacter pylori infection, gastric ulcer and other factors. 1. Improper diet: Some hard-to-digest or irritating foods, such as fatty meat, fried chicken, chili peppers, etc., may irritate the mucous membrane of the stomach, thus causing symptoms of stomach pain. Since people may eat different food every day, so that may appear in the stomach sometimes painful sometimes not. 2. Helicobacter pylori infection: the toxin of Helicobacter pylori may cause damage to the gastric mucosa, while the gastric mucosa also has a self-protection mechanism, the combined effect of damage and repair, which may lead to stomach pain sometimes and sometimes painless. 3. Gastric ulcer: If the mucosal barrier function of the stomach is impaired, an ulcer may form. Under the stimulation of gastric acid, pain may occur. Since gastric ulcers are characterized by cyclic pain, it is possible that sometimes the stomach hurts and sometimes it doesn’t when gastric ulcers occur. When the stomach sometimes hurts and sometimes doesn’t, you should consult a doctor in time, and improve the rapid urease test, C14 breath test, gastroscopy and other tests under the doctor’s guidance, to clarify the cause of the disease, and actively treat it.