Stomach pain, bloating, nausea and vomiting may be caused by Helicobacter pylori infection, pyloric obstruction, stomach cancer and other factors. 1. Helicobacter pylori infection: Helicobacter pylori is an acid-resistant bacterium that can evade the attack of gastric acid and settle in the gastric sinus. This bacterium may release ammonia and vacuolar toxin, which may cause damage to the gastric mucosa. Mucosal damage not only produces painful symptoms, but also leads to a weakening of the secretory function, which may lead to stomach pain, bloating, nausea and vomiting. 2. Pyloric obstruction: food entering the stomach needs to pass through the pylorus in order to be emptied from the stomach. When the pylorus is obstructed, food may accumulate in the stomach, leading to the increase of intragastric pressure, which may cause stomach pain, bloating, nausea and want to vomit under the action of pressure. 3. Stomach cancer: when there are tumor cells growing in the stomach, on one hand, it can cause damage to the stomach wall, on the other hand, it can also lead to slowing down of peristalsis of the stomach, which makes the stomach content accumulate for a long time, and under the influence of these two aspects, stomachache, bloating, nausea and vomiting may occur. When the situation of stomach pain, bloating, nausea and vomiting occurs, you should consult a doctor in a timely manner, under the guidance of the doctor to improve the C14 breath test, barium meal examination, gastroscopy and other tests, to clarify the cause of the disease, and active treatment.