Stomach pain without bowel movement for two days is commonly caused by the following reasons: gastric ulcer, gastric tumor, intestinal obstruction and so on. 1. Gastric ulcer: patients will feel pain in the stomach, gastric ulcer may lead to pyloric obstruction, which will affect the excretion of food, and may lead to two days without bowel movement. 2. Gastric tumor: it can also cause pain in the stomach, which will affect the digestion and absorption of food, and also the emptying of food, thus affecting bowel movement. 3. Intestinal obstruction: food will accumulate in the gastrointestinal tract, the stomach may be bloated and painful, due to the obstruction of the intestinal tract, so it will lead to stopping defecation. Patients can go to the hospital, can improve the relevant examination, including gastroscopy, abdominal plain film, etc., combined with physical examination and clinical symptoms, usually can be clearly diagnosed.