Enemas are rectal injections of fluid intended to cleanse or stimulate the emptying of your bowel.

They have been used for hundreds of years to treat chronic constipation and prepare people for certain medical tests and surgeries (1).

Enemas can be administered by a medical professional or self-administered at home.

This article reviews different types of enemas, as well as their potential benefits and health concerns.

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Constipation is a condition in which the natural movement of your stool slows down, making them hard, dry, and difficult to excrete. For many people, this can be a chronic problem that requires an intervention like an enema — or a laxative inserted rectally.

Enemas may also be prescribed to flush out your colon before certain diagnostic tests or surgeries. Your bowel needs to be empty before these procedures to reduce infection risk and prevent stool from getting in the way.

According to some enema advocates, when waste builds up in your colon over time, it leads to ailments like depression, fatigue, headaches, allergies, and irritability, and using enemas can provide relief.

While it’s true that many people with chronic constipation experience depression and other psychological symptoms, evidence is lacking to suggest that waste buildup directly leads to the other aforementioned effects (2, 3).

There are two main types of enemas — cleansing and retention.

Cleansing enemas

Cleansing enemas are water-based and meant to be held in the rectum for a short time to flush your colon. Once injected, they’re retained for a few minutes until your body rids itself of the fluid, along with loose matter and impacted stool in your bowel.

Some of the most common cleansing enemas include (3, 4):

  • Water or saline. The least irritating of all options, water or saline — salt water that mimics your body’s sodium concentration — are used primarily for their ability to expand the colon and mechanically promote defecation.
  • Epsom salt. This is similar to a water or saline enema, but magnesium-rich Epsom salt is said to be more effective at relaxing bowel muscles and relieving constipation.
  • Sodium phosphate. This is a common over-the-counter enema that works by irritating your rectum, causing it to expand and release waste.
  • Lemon juice. Lemon juice mixed with warm, filtered water is said to balance the pH of your body while cleansing your colon.
  • Apple cider vinegar. Advocates say that mixing apple cider vinegar with warm, filtered water can quickly clear the bowel and may have other antiviral healing effects on your digestive system.
  • Soap suds. Adding castile soap, or another mild soap with minimal additives, to water mildly irritates the bowel, which encourages the rapid excretion of stool.

Retention enemas

Retention enemas are designed to be held in your bowel for an extended period — usually a minimum of 15 minutes — before being released. Retention enemas may be water- or oil-based, which softens the stool and makes it easier for your body to expel.

Some of the most common retention enemas include (5, 6, 7):

  • Coffee. Coffee enemas are a mixture of brewed, caffeinated coffee and water thought to promote bile removal from the colon. They were popularized by Max Gerson, a physician who used them to help treat people with cancer.
  • Mineral oil. This type of enema works primarily by lubricating waste inside of your colon, sealing it with water, and promoting its removal.
  • Probiotic. Mixing probiotics with water may cleanse your bowel while helping colonize your good gut bacteria. Lactobacillus reuteri enemas have been shown to reduce inflammation in children with ulcerative colitis.
  • Herbal. Some people use herbs like garlic, catnip tea, or red raspberry leaf mixed with water to make herbal enemas with purported nutritional, infection-fighting, and anti-inflammatory benefits.
Summary Enemas are rectal injections of fluid that are intended to cleanse your bowel or treat chronic constipation. The two main types — cleansing and retention enemas — come in a variety of solutions and can be injected at home.

Enemas can treat constipation and clear out your bowel. However, many people choose to use enemas for other purported health benefits (8, 9).

Some advocates claim that enemas can support weight loss, remove toxins and heavy metals from your body, and improve your skin, immunity, blood pressure, and energy levels.

Still, evidence is limited to suggest that enemas are effective for these purposes or that they benefit everyone who uses them. Most evidence in support of their effectiveness is anecdotal, despite their widespread use in modern medicine (10).

Enemas appear to be most effective when used to relieve chronic constipation in a medical setting, though they come with many risks, especially when self-administered at home (11, 12).

Summary Enemas can be effective in cleansing the bowel and treating chronic constipation, but most evidence in their favor is anecdotal rather than science based.

Though enemas can clean out your bowel, you should consider their risks and take certain precautions before using one.

May interrupt your body’s natural balances

Enemas may disturb your gut bacteria and throw off your body’s electrolyte balance.

Research shows that enemas used in preparation for medical procedures significantly disrupt gut bacteria, though the effect appears to be temporary. However, enemas that are split and administered in two doses seem to have fewer effects on the microbiome (13, 14).

Electrolyte disturbances have been observed with various types of enemas, such as large-volume soap suds enemas and those containing minerals.

For instance, there have been reports of Epsom salt enemas causing death from magnesium overdose. In another case, an older man died from severe electrolyte disruption caused by taking two sodium phosphate enemas (3, 15, 16).

Other reports note that the overuse of enemas to flush out the colon may lead to severe dehydration, which can be fatal (17).

Enema solutions can harm your bowel

Lemon juice, apple cider vinegar, and coffee enemas are highly acidic, and scientific evidence to suggest their effectiveness or safety is lacking.

What’s more, the evidence shows that their acidity and makeup can harm your bowel and lead to rectal burns, inflammation, infections, and even death (1).

Similarly, there are reports of children being given acidic hydrogen peroxide enemas, which resulted in an inflamed colon, bloody diarrhea, vomiting, and long-term complications (18).

Furthermore, in some people, herbal enemas have caused internal bleeding that required a blood transfusion and removal of the colon (1).

Dirty or improperly used tools can cause infection and damage

If you self-administer an enema at home, it’s critical to make sure that the tools you use are sterile, meaning they’re free of harmful germs. The use of dirty tools increases your risk of contracting a potentially dangerous infection.

Improper tool use may also cause physical damage to your rectum, anus, or colon. Studies indicate that perforation of the bowel is not a rare complication of frequent enema use that could put your internal organs at risk of infection (3, 12, 19).

Sterile enema injection kits, which usually include a bucket, tubing, solution, and sometimes a bulb, can be found online or at many local drug stores. They come with directions for cleaning and safe use.

Summary Though enemas can be safe and effective, they come with many risks, especially when administered at home. Improperly used enemas can cause potentially life-threatening physical and chemical damage to your rectum or colon.

If you’re mainly considering an enema to stimulate and clean out your digestive system, there may be other, less invasive options.

Some potential alternatives to enemas, which can promote waste excretion and bowel regularity, include (20, 21, 22, 23):

  • drinking caffeinated coffee, which is known to stimulate defecation
  • staying well hydrated with water
  • getting regular exercise like walking, running, biking, or aerobics
  • trying an over-the-counter oral laxative like magnesium
  • increasing your fiber intake by eating whole plant foods like fruits, vegetables, whole grains, nuts, and seeds.

If you have severe constipation or other medical issues, speak to your medical provider to determine whether an enema would be a safe and appropriate treatment.

Summary Less risky alternatives to enemas that can help stimulate bowel movements include staying hydrated, getting regular exercise, and following a healthy, high-fiber diet.

Enemas are used to relieve constipation and cleanse the colon. Water- or oil-based solutions are injected into the bowel through your rectum to expel impacted waste.

Mild enemas like water or saline carry the least risk, but you should consult your healthcare provider before using one at home. Furthermore, ensuring the proper use of sterile injection tools is very important for safety.

Many people swear by enemas to promote regularity and prevent constipation, but evidence of their effectiveness is limited.

Other, less risky alternatives may be a better option in most cases.