Strong stomach pain at night is associated with gastric ulcer and duodenal ulcer diseases. There are quite a few diseases that can cause pain in the stomach, but the pain caused by each disease has a certain character. Many people experience pain in the stomach at night, about an hour after dinner, and this condition is associated with gastric ulcers. After eating food, the food will stimulate the secretion of gastric acid, and when too much gastric acid is secreted it will irritate the ulcer surface, thus causing pain, and the nature of the pain caused by gastric ulcers is more intense. In some people, stomach pain at night is around midnight and is associated with duodenal ulcers. Stomach acid production is higher at night, and since the stomach has been emptied of food, the acid enters the duodenum at a high intensity. Once you have a duodenal ulcer, it will cause pain due to the stimulation of stomach acid, and many people will even wake up in their sleep with pain.