A “gut cleanse” involves flushing out your colon (your large intestine) with a lot of a water-based fluid.
Some people call this process a “colon cleanse,” “colonic irrigation,” or “colonic hydrotherapy.”
It’s based on the ancient theory of autointoxication. This is believing in the need to rid your gut of built-up toxins so they don’t lead to ill health.
There’s no good scientific evidence to support this theory. But in some scenarios, a healthcare professional may recommend a gut cleanse.
This article explores the science behind gut cleanses, including when they might be helpful — or harmful.
What does the science say about gut cleanses?
A gut cleanse involves using a lot of warm, water-based fluid — often up to 60 liters — to flush out your large intestine.
It takes about 45 minutes. During this time, it means having a tube placed an inch and a half into your rectum.
In some scenarios, gut cleansing may be helpful. For example, one study found that participants with chronic constipation or fecal incontinence who had gut cleanses for 12 months reported an improvement in gut function and quality of life.
However, only 43% of the participants reported this at 12 months, suggesting that gut cleanses aren’t helpful for everyone.
For people with irritable bowel syndrome, or IBS, there’s some evidence that a gut cleanse can improve constipation, pain and diarrhea.
But it’s important to remember that studies usually only include people with very specific health conditions, and the procedures are done or supervised by specialists.
A gut cleanse can provide relief from gastrointestinal symptoms for some people for short periods. But it doesn’t solve the underlying cause.
Dr. Will Bulsiewicz, a board-certified gastroenterologist and ZOE’s U.S. medical director, explains:
‘‘When you take a person who is not evacuating fully and you flush out their colon, they will experience temporary relief. That doesn’t mean what you have done is beneficial for your overall health. You have just temporarily remedied the symptoms of your chronic condition.”
The dangers of gut cleanses
Aside from the scenarios above, there is no evidence that gut cleanses lead to health benefits. And they involve many risks.
Unwanted gut symptoms
Gut cleanses can cause mild, transient gut symptoms, such as bloating, pain, and diarrhea. They may also lead to soreness or sensitivity around the rectum.
A perforation is a hole in the gut wall — and a gut cleanse can cause a perforation of the large intestine. If this happens, you need immediate medical attention.
Gut microbiome disruption
A gut cleanse disrupts the balance of your gut microbiome. And it can remove beneficial bacteria that are important for your gut health.
“We know from studies that when people do a bowel cleanse, it causes injury to the microbiome,” Dr. Bulsiewicz explains.
“If you do this repeatedly, it may actually worsen your digestive problems. You might feel better in the short term, but you’re actually making your gut microbiome worse in the long term,” he adds.
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Gut cleanses are invasive procedures, so they could introduce unwanted, harmful bacteria into your large intestine. This could lead to an infection.
Alternatives to gut cleanses
Gut cleanses may help if you have a gut disorder, like chronic constipation. But it’s important to weigh the benefits with the risks. Speak with a healthcare professional about the best way to address your symptoms.
For Dr. Bulsiewicz, fiber is the key to better gut health. “If you want a cleanse, I recommend fiber. Fiber will give you good bowel movements, fiber helps your body clear out toxins, and fiber supports your microbiome,” he explains.
There are plenty of ways to support your gut health without the need for cleanses. These include:
Having a diverse diet with plenty of fiber-rich plant foods, including fruits, vegetables, whole grains, legumes, nuts, seeds, herbs, and spices.
Drinking plenty of fluids throughout the day, such as water or infused water, tea, coffee, and dairy or plant milk.
Trying to focus less on foods high in fat, sugar, and salt — particularly ultra-processed foods.
Aiming for 7–9 hours of sleep a night.
Avoiding smoking and large amounts of alcohol.
At ZOE, we know how important your gut microbiome is to your overall health. Our scientists have identified 15 “good” and 15 “bad” bugs that indicate better and worse health.
With the ZOE at-home test, you can discover which bugs live in your gut and which foods can help support your “good” bugs.
Gut cleanses involve using lots of a water-based fluid to flush out the large intestine.
For some people, including those with chronic constipation, gut cleanses may be helpful.
But there’s no evidence that gut cleanses are beneficial for overall health. In fact, there are a number of risks, especially if you have them on a regular basis.
There are plenty of ways to support your gut without cleanses. For example, having a healthy, balanced diet with plenty of high-fiber plant foods can help improve your gut health.
Clinical effects of colonic cleansing for general health promotion: A systematic review. The American Journal of Gastroenterology. (2009). https://pubmed.ncbi.nlm.nih.gov/19724266/
Prospective evaluation of transanal irrigation for fecal incontinence and constipation. Techniques in Coloproctology. (2017). https://pubmed.ncbi.nlm.nih.gov/28550422/
Rectal irrigation: A useful tool in the armamentarium for functional bowel disorders. Colorectal Disease. (2012). https://pubmed.ncbi.nlm.nih.gov/21883812/
Transanal irrigation for refractory chronic idiopathic constipation: Patients perceive a safe and effective therapy. Gastroenterology Research and Practice. (2017). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5237460/
Treatment of irritable bowel syndrome with a novel colonic irrigation system: A pilot study. Techniques in Coloproctology. (2016). https://pubmed.ncbi.nlm.nih.gov/27194235/
What does a colonic involve? (n.d.). https://www.colonic-association.org/about-colon-hydrotherapy/what-does-a-colonic-involve/