What Is the Gastrocolic Reflex?

Nature's Way of Making Room in the Gut Can Be a Problem in IBS

Large breakfast
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You may have wondered why you are feeling the urge to have a bowel movement soon after eating. The gastrocolic reflex is a reflex in which the simple act of eating stimulates movement in the gastrointestinal tract. Specifically, the gastrocolic reflex stimulates contractions in the large intestine. These contractions may lead to a bowel movement a short time after eating. 

When it's working well, it's nature's way of making room for digesting the food that you are now eating.

 Any new mother has seen this reflex in action as this is why infants often need their diapers changed soon after nursing.

An abnormally strong gastrocolic reflex has been implicated as playing a part in some of the symptoms of irritable bowel syndrome (IBS). Let's take a look at what factors increase the strength of the gastrocolic reflex, what this means for a person for IBS, and how you can use this information to address your own digestive symptoms.

What Increases the Strength of the Gastrocolic Reflex?

The reflex is triggered by the act of eating, but there are other factors that play a part as to how strong the intestinal contractions are as a result. The following things can cause these contractions to increase in intensity:

  • Eating a large meal
  • Eating a meal that contains unhealthy forms of fat, such as fried foods, fatty meats, and rich gravies
  • Drinking large amounts of cold liquid at one time

    The Gastrocolic Reflex and IBS

    Research has indicated that a high number of people who have IBS have an exaggerated gastrocolic reflex action in response to meals. This reactivity appears to be the result, at least in part, to abnormal levels of two hormones, cholecystokinin (CCK) and motilin, both of which are responsible for regulating the motility of the digestive system.

    This exaggerated response can manifest itself in worsened symptoms occurring soon after eating (the fancy term for this is postprandial symptoms).

    The Gastrocolic Reflex and IBS-D

    If you have diarrhea-predominant IBS, you can use your new knowledge about the gastrocolic reflex to try to reduce its effect on your symptoms. Try to eat smaller meals, avoiding foods that contain unhealthy types of fat. Before eating, you can sip some peppermint tea or take a peppermint oil supplement, both of which have antispasmodic effects. If your doctor has prescribed you an antispasmodic medication, you may find that taking the medication approximately 20 minutes before eating can help to reduce any postprandial cramping and pain.

    For more information about diarrhea after eating, learn more in depth: IBS and Diarrhea After Eating

    The Gastrocolic Reflex and Constipation

    Conversely, if you find that you experience chronic constipation, you can perhaps use the gastrocolic reflex to your advantage. For most people, natural body rhythms are such that the urge to have a bowel movement is strongest in the morning. Making sure to eat a large breakfast, with some foods with healthy fat, may strengthen your gastrocolic reflex and help to initiate a morning bowel movement.

    Source:

    Palsson, O. & Whitehead, W. "Hormones and IBS" UNC Center for Functional GI & Motility Disorders 

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