A Guide to Gastrocolic Reflex
This article explains gastrocolic reflex and how it works.
The gastrocolic reflex is a usual part of physiology. Reflexes are automatic responses that take place without having to think about them.
The gastrocolic reflex is the automatic urge to have a bowel movement after meals. It causes increased mobility in the large intestine as a response to food. By stimulating a bowel movement, the body makes room for the incoming food.
It is often a noticeable effect in babies, who may move their bowels right after a feeding. Some may even pass stool during a feeding. This effect can be an advantage in toilet training and helping toddlers and young children with constipation.
The effect of the gastrocolic reflex is the urge to pass stool soon after eating. The reflex is most active in the morning. For most people, this means it is strongest after breakfast. It usually takes about 20–30 minutes.
You can use this to help establish daily routines, especially for young children and older adults who may need assistance with self-care. People with spinal cord injuries may also be able to use this reflex. Experts suggest 5–10 minutes of toilet time after morning meals.
A heightened or blunted gastrocolic reflex can play a role in certain conditions. People with IBS often have a stronger gastrocolic response. A decreased gastrocolic reflex can cause functional constipation. Contact your doctor if you have other symptoms of these conditions, including:
- abdominal pain
- sensation that you have not finished moving your bowels
- frequent urge to move your bowels
The gastrocolic reflex is a response to stretch receptors in the stomach. As food enters the stomach, these receptors send signals to the nervous system.
In turn, the nervous system stimulates motor activity in the large intestine. This triggers mass movements to propel contents toward the rectum and out of the body.
Ultimately, the reflex helps empty the digestive tract to make room for the food you consume.
The gastrocolic reflex is a usual physiological process, so no treatment is necessary.
In people with IBS, medications may help calm an overreactive gastrocolic reflex. They include:
- antispasmodics, such as hyoscyamine (Levsin)
- antiemetics, such as ondansetron (Zofran)
- selective serotonin reuptake inhibitors, such as fluoxetine (Prozac)
- tricyclic antidepressants, such as amitriptyline (Elavil)
Medications that can augment the gastrocolic reflex include bisacodyl (Dulcolax) and other stimulant laxatives.
Certain conditions can result from or cause an altered gastrocolic reflex, including:
- Diabetes: Diabetes can cause nerve damage that leads to a blunted gastrocolic reflex.
- Functional constipation: This condition can occur with a decreased or absent gastrocolic reflex that allows stool to remain in the body for too long.
- IBS: This condition may involve a stronger than usual gastrocolic reflex that causes an intense urge to defecate after a meal and tenesmus — a frequent urge to defecate.
- Idiopathic dumping syndrome: This condition causes food to move too quickly through the digestive tract.
The gastrocolic reflex is a response to food stretching the stomach. Many people find this reflex is more active in the morning after breakfast. So, it is not a matter of what you eat that stimulates the reflex.
Probiotics may be helpful for some people. They help restore flora to the gut. This may help regulate some aspects of the gastrocolic reflex physiology.
The gut microbiota plays a role in maintaining levels of neuropeptides. These substances mediate communication between the gut and the brain. Not all probiotics are the same, so talk with your doctor about a trial.
For people with IBS, the effect of diet on symptoms is unique to each person. The effects can also be inconsistent and unpredictable in the same person. So, it is nearly impossible to give specific dietary advice in a general way. Keeping a detailed food diary over the course of several weeks can help identify triggers and modify your diet.
Here are some questions people often ask about gastrocolic reflex.
What is gastrocolic reflex a symptom of?
The gastrocolic reflex is a typical physiological response to food stretching the stomach that stimulates a bowel movement. It can be overactive or more intense than usual in IBS and idiopathic dumping syndrome.
Is gastrocolic reflex normal?
The gastrocolic reflex is a usual part of physiology. It stimulates the colon to move waste out of the body to make room for the incoming food. It is usually most active in the morning.
The gastrocolic reflex controls the mobility of the colon in response to food. When the stomach stretches with a meal, it triggers mass movements in the colon. This moves stool to the rectum, where pressure activates the urge to defecate.
The purpose of the reflex described above is to make room in the digestive tract for the new meal. For many people, the reflex is strongest in the morning.