A large and painful stomach may be caused by improper diet, intestinal obstruction, abdominal fluid accumulation and other reasons. 1. Improper diet: patients with poor digestion of gastrointestinal function, eating too much greasy, indigestible food, so that the patient appears abdominal distension, nausea, abdominal pain and other symptoms. 2. Intestinal obstruction: due to constipation, tumor, inflammation stimulation, intestinal adhesion and other reasons, patients suffer from intestinal obstruction, resulting in abdominal pain, vomiting, abdominal distension and other symptoms. 3. Abdominal fluid: ascites can be formed due to liver cirrhosis, nephrotic syndrome, hypoproteinemia, chronic right heart failure, etc. Due to the imbalance of fluid balance in the body, the patient will suffer from abdominal distension, abdominal pain, loss of appetite, nausea, vomiting, etc. It is recommended that the patient should have a bigger and painful stomach. It is recommended that patients with symptoms of stomach enlargement and pain go to the hospital in a timely manner to get a clear diagnosis and choose the appropriate treatment under the guidance of the doctor to avoid delaying the condition.