Cleaning out the colon is sometimes necessary — for example, before a medical procedure, such as a colonoscopy. But some people do it in the belief that the process will rid their colon of excess toxins that accumulate over time from the foods they eat, the air they breathe, the water they drink and the lifestyles they lead.
Medical professionals say that the body comes well-equipped with its own built-in mechanisms to eliminate harmful substances: the liver and kidneys. In fact, colon cleansing that is done to help remove toxins is an unnecessary and potentially dangerous practice, especially colon hydrotherapy.
"Every week, someone asks me whether colon cleansing is safe and whether a person should be doing it," said Dr. Jacqueline Wolf, a gastroenterologist at Beth Israel Deaconess Medical Center in Boston and the author of "A Woman's Guide to a Healthy Stomach" (Harlequin, 2011).
Wolf tells her patients there is little research on colon-cleansing methods, and that most physicians don't believe in these treatments or advise their use.
Prepping for a colonoscopy
One circumstance in which medical professionals recommend cleaning out the colon is before a colonoscopy, a procedure in which a tiny camera at the end of a lighted tube is inserted through the anus, through the rectum and into the large intestine to enable the doctor to look for pre-cancerous polyps, cancer or other diseases, according to the American College of Surgeons. The need for cleaning out the colon in this case is simple: "If you don't clean out the stool, you can't see anything. You need to be able to see the [intestinal] wall, and to do that you need a clean colon," Wolf said.
Three days before a colonoscopy, patients typically follow a low-fiber diet so that their stool will not be too hard. The day before a colonoscopy, patients follow a liquids-only diet. The night before, patients drink a colonoscopy prep solution, which is a laxative that induces diarrhea in order to empty the bowel. Different colonoscopy preps work in slightly different ways, but they all stimulate bowel movements, Wolf said. Diarrhea is not a problem in this case, but the goal. Without it, the colon won't be empty and the doctor may not be able to see what they need to.
Colonoscopy preps can have a few potential side effects. For example, they may change the body's levels of electrolytes, which are ions of chemicals such as potassium and sodium that conduct electricity when dissolved in water, Wolf said. On one hand, drinking lots of water before a colonoscopy has the potential to dilute electrolytes like sodium and magnesium. On the other hand, diarrhea could have the opposite effect and result in increased concentrations of those chemicals, Wolf said. Shifting levels of sodium might cause lightheadedness, and low potassium levels may cause leg cramps or abnormal heart rhythms, she said.
Additionally, any laxative that draws water into the colon brings the risk of dehydration, if the individual does not drink enough fluids, Wolf said. She recommends that people drink water with added electrolytes when preparing for a colonoscopy.
Other side effects of colonoscopy preps can include bloating, nausea and vomiting, and abdominal pain, according to the American Society for Gastrointestinal Endoscopy.
People go through the discomfort of colonoscopy prep and the procedure itself because it's a means to an end. Colonoscopies enable doctors to detect and remove precancerous polyps and to spot colorectal cancer early, when treatment is most likely to work, according to the Centers for Disease Control and Prevention (CDC). The colon cleansing that happens before a colonoscopy does not have any other health-related purpose, Wolf said.
Purported benefits of colon cleansing
Colon-cleansing enthusiasts believe that periodically cleaning from the inside out removes excess waste stuck to the colon walls. This waste buildup also supposedly produces toxins that enter the blood and may slowly poison people. Wellness companies claim that colon cleansing can help relieve a variety of symptoms — such as fatigue, bloating, irritated skin and weight gain — and alleviate a range of health problems, from depression and allergies to arthritis and cancer.
Cleansing proponents promote two, or perhaps three, ways to clean the colon. One method involves taking bowel-clearing laxatives, powders or supplements; using enemas; or drinking herbal teas to purportedly release colon waste and discharge toxins. But using this method might feel more like frequently running to the bathroom with diarrhea.
A second method is called colonic irrigation or colon hydrotherapy--sometimes just referred to as 'colonics'--in which a practitioner flushes out the colon by sending gallons of water into the body through a tube inserted into a person's rectum. This procedure can cost from $55 to $95 per session, according to The Colon Therapists Network.
A third method is dietary colon cleanses, such as juice cleanses and high-fiber diets.
Wolf said people's curiosity about cleansing possibly stems from the idea that the bowel is a dirty place, and that getting rid of waste is a good idea. She said she usually doesn't recommend colon hydrotherapy, but has suggested it for a few people to use as colonoscopy preparation when traditional methods have failed. She also recommended it for patients who had severe constipation, before there were strong drugs that could help remedy this problem.
But does colon cleansing flush out toxins, as its supporters suggest, or does it flush money down the toilet?
"We don't know enough about colon cleansing to know the real truth," Wolf told Live Science. "It's an area we should learn more about."
A review study published in 2009 in the American Journal of Gastroenterology concluded that there were no rigorous studies to support the practice of colon cleansing as a way of improving or promoting general health.
And because cleansing products and methods rarely name the specific toxins they supposedly remove from the body, there's been no research measuring how effective cleansing practices may be at actually eliminating these substances, or demonstrating the health benefits of removing them, Wolf said.
There's also no evidence that a colon cleanse can cause meaningful weight loss. A cleanse may help a person lose a few pounds initially, but that is a temporary loss, resulting from the removal of water weight and stool, and not from a permanent loss of fat. Although it could be motivating to see results on the scale for a few days, cleansing is not a long-term solution to a weight problem, Wolf said.
The real risks
"We don't have real data on either the healthy or unhealthy side effects from cleansing methods," Wolf said. Most of the known side effects come from case reports described in the medical literature and not from research studies, of which there are few.
As is the case during colonoscopy prep, colon cleansing with laxatives, herbal formulations or enemas might increase a person's risk of becoming dehydrated and alter electrolyte levels, Wolf said.
Colon hydrotherapy may cause abdominal cramping, stomach pain, diarrhea, nausea and vomiting, according to Mayo Clinic. More severe complications may include infections, electrolyte imbalances, kidney and liver failure, and bowel perforation, as Live Science previously reported. For example, one case study reported that a 55-year-old man with chronic constipation perforated his bowel giving himself an enema with a garden hose.
The Food and Drug Administration requires colon hydrotherapy systems to meet certain requirements and has not approved any of them for nonmedical purposes, such as colon cleansing, according to a 2011 article by several physicians published in MDedge Family Medicine, a news site for family physicians. The devices are required to receive premarket approval for any uses beyond their original indications (preparation for endoscopic procedures, such as colonoscopies, and radiologic procedures) and has issued several warning letters to manufacturers of colon hydrotherapy systems that have not received premarket approval for use for colon cleansing, according to MDedge Family Medicine.
In addition, Wolf said that colon cleanses are particularly risky for people with kidney disease or heart problems because these individuals already have trouble maintaining fluid balance in their bodies, and the electrolyte shifts caused by colon cleanses could be an issue. People with gastrointestinal problems, such as Crohn's disease (a condition involving inflammation in the gastrointestinal tract), ulcerative colitis (which involves inflammation in the large intestine), and recurrent diverticulitis (in which a person develops inflamed pouches in the wall of the colon) also have increased risks of problems resulting from a colon cleanse.
Colon hydrotherapy is also potentially unsafe for people with Ehlers-Danlos syndrome, a connective tissue disorder, because of the possible risk of a puncturing a hole in the bowel, as well as for anyone who's had prior colon surgery or severe hemorrhoids, Wolf said.
Trillions of bacteria live in the colon, and eliminating them or changing the population of beneficial and harmful bacteria in that organ could be a problem.
"A colon cleanse would never get rid of all the bacteria, but research is increasingly finding that a lot of bacteria in the colon is very healthy," Wolf said. Some of the good colon bacteria play a role in keeping bad bacteria at bay.
Scientists don't know if colon cleanses and colon hydrotherapy disrupt the bacteria in the colon or cause an imbalance in the microbiome, Wolf said. "It hasn't been studied," she said.
What about a "dietary" cleanse?
Laxatives, enemas and colon hydrotherapy have risks, but what about colon-cleansing methods based on dietary changes alone? A third method of colon cleansing involves trying to purify the colon by consuming certain foods and liquids. A juice cleanse, for example, might involve drinking only juice — often unpasteurized "raw" juice — for several days. A fiber-based cleanse would involve a diet full of fruits, vegetables and whole grains.
As with other cleansing methods, the research on dietary colon cleanses is sparse and of low quality, according to the National Institutes of Health's National Center for Complementary and Integrative Health (NCCIH). The existing research reports that "juicing and 'detox' diets can cause initial weight loss because of low intake of calories but that they tend to lead to weight gain once a person resumes a normal diet," the NCCIH stated.
Wolf recommends that green leafy vegetables and high-fiber foods be included as part of a healthy diet, in general. But there's no clear evidence to suggest these foods are beneficial in the form of dietary colon cleanses, she said.
Additionally, drinking only juice for several days is not a balanced diet. According to the NCCIH, some juices contain high levels of oxalate, a waste product expelled from the body in urine that is also found in high levels in some foods, such as spinach and beets. Drinking lots of high-oxalate juice can increase the risk of kidney problems, according to the NCCIH. University of Michigan Health warns that too much oxalate can cause kidney stones in some people.
Further, juices that haven't been pasteurized may contain bacteria that could make people sick, according to the NCCIH.
As for fiber "cleanses," these sometimes amount to eating the recommended daily dose of fiber. Recommended intake of dietary fiber is 38 grams (1.3 ounces) for men and 25 grams (0.9 o.z) for women, according to the NIH, but many people don't consume that much fiber on a regular basis. Unlike a juice cleanse, a fiber-based cleanse is not restricted to one type of food, and a high-fiber diet actually does have health benefits: It can relieve constipation, promote regular bowel movements, and some research suggests that it reduces the risk of cardiovascular disease and type 2 diabetes, according to the NIH. Studies have also found that people who eat more fiber, which adds bulk without calories, tend to consume fewer calories and weigh less.
So if eating a diet with sufficient fiber counts as a cleanse — and WebMD does liken eating the recommended daily dose of fiber to cleaning out your colon with a toothbrush — then a dietary colon cleanse centered around fiber is one that experts do recommend.
This article is for informational purposes only, and is not meant to offer medical advice. This article was updated on Nov. 9, 2021 by Live Science contributor Ashley P. Taylor.