This situation may be caused by physiological reasons such as eating greasy food in the afternoon, and may also be caused by pathological reasons such as irritable bowel syndrome and intestinal polyps. 1. Physiological reasons: may be in the afternoon eating fat and greasy food, or in the evening in time too late, etc., food is not timely digestion and absorption, accumulation in the stomach, the night will feel the stomach bloating. Eating too many soybeans, onions and other foods at one time, produce too much gas will also appear bloating. 2. Pathological reasons: irritable bowel syndrome, colitis and other causes of slow peristalsis of the gastrointestinal tract, slow digestion and absorption of food eaten during the day may appear at night bloating. Intestinal polyps, intestinal obstruction, etc. lead to intestinal tract is not smooth, food residues can not be discharged in a timely manner, there may be a bloated stomach. This phenomenon excludes physiological reasons such as improper diet, but may also be caused by other diseases, you should consult a doctor in a timely manner, under the guidance of the doctor to identify the causes and carry out reasonable treatment.