What Is an Enema and How Does It Work?

An enema is the introduction of a liquid through the anus and into the large intestine. An enema may be given to treat constipation or to administer medication. It also may be used as part of the procedure to empty the contents of the bowel before a test, as with​ a colonoscopy prep.

Some people get carried away with enemas, filling them with liquids (like coffee) that are not recommended by healthcare providers. There is no evidence that using an enema for "detoxing," or for reasons other than removing impacted stool, or cleaning the bowel before a test or procedure, has any health benefits whatsoever.

This article explains how enemas work and some of the liquids that can be used to ensure it accomplishes what it's supposed to.

Enema on a pink background, medical concept, top view, minimalism
Vladimir Sukhachev / Getty Images

How Are Enemas Used?

An enema purchased from a pharmacy has a nozzle on the end of a small bag or bottle. This container is filled with liquid—sometimes salt and water, sometimes mineral oil—that is injected into the body. The nozzle is inserted into the anus and the container is squeezed, sending the liquid out of the nozzle and into the last part of the colon, called the rectum

The liquid is usually held in the rectum for an amount of time specified in the product instructions. It could be held until the urge to move the bowels comes on. In some cases, it might be suggested that the enema stay inside the body for a few minutes or longer.

When it's time, the enema and the waste material that is in the rectum are released by sitting on the toilet and moving the bowels like usual.

Play it safe with enemas by:

  • Reading and following the directions on the "drug facts" label.
  • Using the correct dose and dosing frequency.
  • Refraining from using more than one dose of the product in 24 hours.
  • Not giving an enema to a child younger than 2.


Liquids Used In Enemas

In some cases, the liquid used in an enema is just saltwater or water mixed with baking soda. Some enemas contain a laxative. The type of liquid may vary, depending on why the enema is used.

Check with your healthcare provider if you are unsure about which enema to use, and be sure they are aware of your enema use. Some common enema liquids include:

  • Bisacodyl: Bisacodyl is a laxative that is frequently used in enemas, especially in those that are used in preparation for a procedure such as a colonoscopy.
  • Mineral oil: Mineral oil is both a lubricant and a laxative. This makes it especially useful in enemas that are used to treat constipation, when the anus is sore, or if hemorrhoids are present.
  • Saline solution: In cases of constipation, a saltwater enema might be recommended. Health experts advise against making your own enema solution with tap water.

Medications

In the treatment of some conditions, including inflammatory bowel disease (IBD), medication might be given with an enema. Asacol (mesalamine) and Rowasa, both 5-aminosalicylic drugs, are used to treat ulcerative colitis. They are given in this way.

This treatment usually addresses inflammation that is found in the last section of the colon, where the enema liquid will reach. It's often recommended that these enemas are used at night to give the medication time to work.

Other Substances

There are practitioners who offer enemas with substances that might surprise you, like coffee, lemon juice, and milk. The idea is to remove toxins from the body and fortify the liver and gallbladder.

People with IBD should be especially wary of these types of enemas. There is the potential to introduce harmful materials into the body with the use of a nonmedical enema. In addition, the colon contains various forms of beneficial bacteria, and the use of an enema may disrupt the bacterial flora and harm the delicate lining of the colon.

What to Expect

In most cases, how to use an enema is a straightforward process. People typically give enemas to themselves, although some people may need help if they have mobility or cognition issues.

Keep in mind that an enema takes time to work and keeps you in the bathroom for a bit. You'll want to make sure you've set the time aside for your enema, so give yourself at least a few hours.

Preparation

To perform an enema, first be sure that you have the right enema product and understand the instructions. You'll also want to ensure that you have space to lie down, typically on the bathroom floor, and some towels.

Administration

The instructions for most anal enema products include the same series of steps. You'll first apply a lubricant, such as petroleum jelly, to your anus to limit any discomfort and ensure the enema nozzle goes in smoothly. You'll also take the cap off of the enema nozzle. Other steps include:

  • Lying in the best position to reach around to your anus, typically on your side with one knee bent
  • Gently inserting the enema nozzle into the anus and rectum, and squeezing all the fluid into them
  • Taking the enema nozzle back out and then waiting the recommended amount of time
  • Emptying your bowels over the toilet once the waiting time has passed

Precautions and Risks

Most people will not experience any difficulties with the enema procedure but there are a few things to avoid.

You don't want to insert the enema nozzle too far up into your anus, causing pain. And it's rare, but be sure to use the bottle and bag, and the nozzle, exactly as instructed because it's possible for a part to become stuck, causing a foreign body obstruction.

It's also important to use exactly the amount of fluid that's called for in the instructions. If you use too little, the enema may not be effective. If you use too much, the enema may take longer to work because the fluid has reached higher into your colon.

Other considerations include:

  • Damage to the rectum or intestines due to bloating from the fluid
  • Discomfort because of using fluids that are too cold or hot
  • Infection if the enema equipment is not kept sterile

Complications with enemas are rare but they can be serious. Among them are the risk of a perforation (puncture) in your intestines, or infection that leads to sepsis, a potentially life-threatening condition. Contact your healthcare provider right away if you have pain, fever, or other symptoms that don't resolve on their own.

Benefits

Enemas are helpful for relieving discomfort and improving your ability to pass stool (poop). They're safe for occasional use when treating constipation, IBD, or when you're preparing for a procedure.

Keep in mind, though, that there's little data to support the use of enemas when they're touted as a method to deliver other health benefits.

People who try coffee, alcohol, hydrogen peroxide, or other fluids in an enema—sometimes after reading "recipes" from the Internet—often cause themselves injury and do more harm than good.

Risks

Many people use enemas safely and avoid complications or enema side effects, but there are a few things to watch out for.

People with certain health conditions should speak to their healthcare providers before using an enema product. They may be at higher risk for dehydration or related electrolyte imbalances, which can disrupt body functions that rely on these key minerals.

This is true of people with IBD, but also those with heart, kidney, and other health conditions. Some patients receiving cancer treatment that requires an enema ahead of surgery also may be at higher risk of complications. In other cases, frequent use of enemas to relieve constipation in people receiving chemotherapy may lead to concerns.

Keep in mind that even if you don't have a known health condition, your use of enemas may be masking a more serious health issue that's the cause of your constipation and related symptoms. Among them is colorectal cancer, which often causes constipation and other bowel habit changes.

It's worth trying other lifestyle changes, such as diet and exercise, instead of relying too much on enemas to improve your digestive health. Enemas are generally safe products, but there are more health risks from using enemas than there are with other constipation treatment options.

Summary

An enema delivers liquid through a nozzle and into the anus and rectum. It's often used to treat constipation, with types of enemas that include salt water, mineral oil, and laxative elements.

If you're using them under the care of a healthcare provider and for a defined purpose, like to prepare for a colonoscopy, then enemas can work. It's important that you only use enema products recommended by a professional, and avoid other uses without proven benefits.

A Word From Verywell

Enemas are safe, effective, and relatively easy to use if you follow the guidelines. Be sure to use an enema only as directed and follow the instructions for the specific product.

Frequently Asked Questions

  • How long does it take for an enema to work?

    The answer will depend on what type of enema product you use. Some enemas will promote a bowel movement in just 15 minutes or less. Others, such as the bowel prep kits that contain bisacodyl, may take up to an hour before they begin to work. The specific instructions will give you an idea of what to expect.

  • What enema side effects in kids should I know about?

    There are few side effects from the enema procedure itself. Most people report some cramping and bloating as their main discomfort, while others experience nausea, vomiting, dizziness, and other symptoms. These symptoms may be more of a concern in children who need enemas for treatment or prior to colonoscopy.

  • Is an enema the same thing as a colonic?

    No. They're both used to cleanse the colon, but for different reasons and with a focus on different parts of the colon. A colonic also may present health risks in the absence of evidence-based benefits. Some experts suggest that avoiding pollution and other toxins, while eating a healthy diet, is a better choice.

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