I think most of us have experienced usually in the morning after taking tea, water or breakfast urge to go toilet for defecation. When we eat food, our stomach gets stretched. The nerves in the stomach send signals to the brain then to the large intestine saying that your stomach is full and now needs to accommodate this new food. That why the unwanted food needs evacuation.
So, muscles in your large intestine contract that causes bowel movements and we defecate. This action is called gastrocolic reflex. This phenomenon is natural.
The food, we eat usually stay in our body for about 24 hours. There are different types of movement throughout our gastrointestinal tract. Mass movements is the one which occur 3-4 times a day push your stool very quickly to the rectum and make us feel to defecate. Gastrocolic reflex, smoking, parasympathetic nerve activation do activate this mass movement.
Moreover, if you get the urge to empty your bowel urgently after every meal, something is wrong. Constipation alternate with diarrhea, bloating, may be symptoms of irritable bowel syndrome. Bowel movements immediately after eating may be a symptom of Crohn’s disease but there is the difference it is characterized by loose motions, blood in the stools, and abdominal pain.
So, just be aware when to see the doctor with your condition.