Left abdominal pain during the day without pain at night may be caused by gastric ulcer, functional dyspepsia, chronic enteritis and other diseases. 1. Gastric ulcer: when the patient has a gastric ulcer, sometimes the pain will appear at night, while the pain symptoms may not be obvious during the day. 2. Functional dyspepsia: disorders of nerve function often affect the peristaltic rhythm of gastrointestinal smooth muscle, some patients at night, there may also be symptoms of abdominal pain, which can be manifested as nausea, abdominal distension, acid reflux during the day and other symptoms. 3. Chronic enteritis: If patients with chronic enteritis occurs, the left abdominal pain usually occurs at night, the patient may not feel obvious pain during the day. If the patient has left abdominal pain during the day without pain at night, he should go to the hospital in time, after clarifying the cause of the disease, under the guidance of the doctor to carry out the appropriate treatment and therapy.