There are many reasons why the stomach hurts badly all at once. Gastritis and gastric ulcer can cause severe pain in the abdomen, intestinal spasm can also cause pain in the abdomen, and appendicitis can also cause it. Therefore, patients should take different treatments according to different situations, and if necessary, come to the hospital for examination and symptomatic treatment. If it is gastritis or gastric ulcer, the pain is usually located in the upper abdomen, accompanied by nausea, vomiting, abdominal distension, etc. Gastroscopy can generally clarify the lesions in the stomach, and treatment requires oral medication, such as omeprazole, etc. If the pain is caused by intestinal spasm, it is usually caused by cold in the abdomen or sudden increase in peristalsis of the gastrointestinal tract, and the pain can be relieved after applying hot towels to the abdomen. If the pain persists without relief, it may form intestinal obstruction and intestinal necrosis, so you need to go to the hospital for examination in time. Appendicitis can also cause abdominal pain, usually in the right lower abdomen, the appendix ultrasound can find an enlarged appendix, surrounded by oozing, can clearly diagnose, after the diagnosis need to perform appendectomy.