Bowel movement at noon after morning defecation can be caused by gastroenteritis, colitis, sinusitis and intestinal function abnormalities and other factors, or it may be a normal phenomenon. 1. Gastroenteritis: acute gastroenteritis can be triggered by infection with bacteria or viruses and other pathogens. Acute gastroenteritis can lead to gastrointestinal dysfunction, which can lead to frequent bowel movements. 2. Colitis: after the occurrence of colitis can lead to rectum and sigmoid colon function is affected, the intestinal mucosa can appear local bleeding and ulcers and other manifestations, there can be an increase in the number of bowel movements, but also accompanied by symptoms of abdominal pain. 3. Sinusitis: Sinusitis can be triggered by bacterial infection in the anal sinus, which may cause frequent defecation and incomplete defecation, as well as anal canal drop feeling and pain. 4. Abnormal intestinal function: Irritable bowel syndrome or eating too much high-fat, spicy and stimulating food can also lead to intestinal dysfunction, triggering frequent bowel movements. 5. Other conditions: under normal circumstances, you can have one or two bowel movements a day, and due to different dietary habits and bowel habits, you may have a bowel movement in the morning and then at noon. If you still have a bowel movement at noon after morning defecation, you should consult a doctor in time, and under the guidance of a specialized doctor, you should actively carry out the appropriate treatment, which will help to cure the disease as soon as possible.