Midnight bloating may be caused by improper diet, gastritis, intestinal diseases and other reasons. 1. Improper diet: If you take too much potatoes, soy products, cold food and other gas-producing food before going to bed, due to the slowdown of gastrointestinal peristalsis at night, the gas discharge is slow, there may be midnight bloating, after a period of time can be relieved. 2. Gastritis: gastric mucosa edema, congestion and erosion and affect the gastric secretion of digestive juices and peristaltic function, the symptoms of midnight bloating. 3. Intestinal diseases: ulcerative colitis, intestinal polyps and other intestinal diseases may lead to slow intestinal peristalsis, intestinal lumen narrowing. Midnight gastrointestinal peristalsis will also slow down the symptoms of midnight bloating. Midnight bloating may also be caused by other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.