There are several reasons for sudden stomach pain in the middle of the night: 1, duodenal ulcer, usually appear in young adults, hunger in the middle of the night will lead to stomach pain, a little food, the symptoms of pain will be relieved. 2, gastric mucosal prolapse, gastric mucosa infected with Helicobacter pylori, pyloric dysfunction, inflammation of the gastric mucosa may trigger gastric mucosal prolapse, will lead to stomach pain, especially the right side of the night to sleep will 3, eat very spicy food at night, capsaicin stimulates the gastric mucosa very much, which may lead to stomach pain, the performance of pain is burning pain in the stomach, especially lying down to sleep, digestive juices will reflux, the pain is more intense. 4, eat particularly difficult to digest food at night, such as food made of glutinous rice flour, these foods will bring a great burden to the stomach, it takes a long time to be digested. In the middle of the night there will be a lot of digestive juices gathering in the stomach leading to stomach pain, and bloating.