Fecal transplants use feces from a donor to help adjust the balance of organisms in your gut. Research is mixed on whether they can help treat IBS, but research is ongoing.

Irritable bowel syndrome (IBS) is a common gut disorder that causes symptoms such as abdominal pain, bloating, constipation, and diarrhea. Although IBS has no cure, dietary changes and medications can usually ease symptoms.

Researchers are currently exploring whether fecal microbiota transplant (FMT) can also help with IBS. This relatively new procedure involves using a donor stool sample to restore gastrointestinal (GI) tract microbiota.

This article explores current research into the effectiveness of FMT for IBS, along with the ins and outs of this procedure.

Microbiota refers to the trillions of microorganisms — bacteria, viruses, and fungi — that live in a healthy GI tract.

People with IBS often have an imbalance in intestinal microbiota, something experts refer to as dysbiosis. Using a stool sample from a healthy donor, fecal transplantation could help improve gut dysbiosis.

However, the results of current studies into FMT as a treatment for IBS are mixed:

  • A 2019 review of four studies found that FMT may help treat IBS, but more studies were needed to know for sure.
  • Another 2019 review looked at 13 studies and determined that FMT was ineffective.
  • A third 2019 review of four studies also found FMT was no more effective than placebo at relieving IBS symptoms.
  • A 2021 review of seven studies also found inconsistent results. Researchers suggest the benefits of FMT for IBS might depend on the choice of donor and the dose of fecal matter.
  • A 2023 review of eight studies found that FMT was effective when delivered by endoscopy but not by capsule. Still, researchers note there wasn’t enough evidence to either recommend or discourage FMT for IBS.

Together, these results show a need for more high quality research. In particular, it’s not clear why some people with IBS appear to benefit from a fecal transplant and others do not.

Is fecal transplantation approved by the FDA?

Fecal transplantation is only approved by the Food and Drug Administration (FDA) to treat recurrent bacterial infections caused by C. difficile.

The FDA has not approved any fecal microbiota products or procedures for treating IBS or any other GI disorder.

In fact, the FDA warns against the use of fecal transplant products such as capsules and enemas for unapproved purposes and highlights serious safety risks associated with these products.

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A fecal transplant is typically performed in a hospital, clinic, or doctor’s office. During this procedure, a doctor inserts a stool sample from a healthy donor into your GI tract.

The transplant is often done via a colonoscopy. Before a colonoscopy, healthcare professionals give you a sedative to help relax your muscles.

A doctor then inserts a thin, bendable tube called a colonoscope into your anus and up your colon. The tip of the colonoscope has a light and a camera along with a port to deliver liquids.

At the end of your colon, the doctor releases a solution containing the donor feces and withdraws the colonoscope.

There are several other ways to receive a fecal transplant. Your doctor might suggest delivering donor fecal matter via:

The outlook for people with IBS after a fecal transplant isn’t clear. The procedure is still undergoing clinical trials, and the results of studies are inconsistent.

Some studies have shown promising results. For example, the authors of a 2022 study followed up on 125 people who had received either a placebo or a fecal transplant for IBS after 3 years.

Researchers reported the following rates of improvement in the various participant groups:

GroupNumber of participantsDecrease in symptom severity after 2 yearsDecrease in symptom severity after 3 years
30 grams of donor feces4269%65%
60 grams of donor feces4578%72%

While this study suggests FMT could have a lasting impact on IBS symptoms, there’s not enough research to know for sure at this point.

Other large-scale studies are needed to learn more about the long-term benefits and risks of FMT for IBS.

Fecal transplantation carries a relatively low risk of serious side effects. According to a 2021 review, the most common side effects are mild and temporary, including:

  • abdominal discomfort
  • bloating
  • constipation
  • diarrhea
  • gas
  • low fever

Serious side effects are usually linked to the FMT procedure. For example, a colonoscopy carries several risks, such as bleeding, infection, and rectal tears, among others.

Your doctor can help you learn more about the risks associated with your FMT procedure.

Your doctor will provide detailed instructions on how to prepare for your fecal transplant.

Keep in mind that the preparation process depends on the procedure used to insert the stool sample, whether it’s a colonoscopy, endoscopy, or another method.

If your FMT is done by colonoscopy, your care team might tell you to:

  • temporarily stop taking certain medications
  • avoid high fiber foods and eat only soft foods in the days leading up to the procedure
  • only have liquids the day before the procedure
  • take a laxative to empty your bowels the night before the procedure
  • avoid consuming food and liquid a few hours before the procedure

These are just general guidelines. They might not apply to your situation. It’s important to follow the plan provided by your care team and ask for clarification if you’re not sure.

Your doctor will review what you can expect after an FMT. For example, you might experience GI symptoms, such as abdominal cramps, bloating, and diarrhea. Some people develop a low fever.

These symptoms should go away on their own within a day or two. If they don’t, contact a doctor.

Am I eligible for a fecal transplant?

If you have a C. difficile infection that’s not responding to antibiotics, you might be eligible for a fecal transplant.

This procedure still isn’t widely available for people with IBS, and it doesn’t have FDA approval. Still, you might be eligible to participate in a clinical trial to help researchers learn more about FMT for IBS.

If you want to learn more about research-backed IBS treatments, talk with a doctor.

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If you receive FMT for a C. difficile infection, your insurance should cover the procedure. However, always check with your insurance provider for more information about eligibility requirements, copays, and deductibles.

If you decide to participate in a clinical trial of FMT for IBS, you’re not likely to have to pay anything for the procedure since it’s an experimental treatment.

Keep reading for more information on fecal transplants for IBS.

What is the success rate of fecal transplant for IBS?

Results are mixed as to the success rates of fecal transplants for IBS. There aren’t yet enough high quality studies to recommend this procedure for everyone with IBS.

How close are we to curing IBS?

There’s still a lot we don’t know about IBS, and we’re still a long way from a cure. Most treatments focus on preventing and alleviating symptoms through diet, lifestyle strategies, medications, and other therapies.

How are donors for fecal transplant chosen?

Fecal transplant donors are typically young, healthy volunteers who meet specific eligibility requirements. They must provide detailed information about their medical history and give blood and stool samples for testing.

IBS has been linked to imbalances in gut microbiota. Fecal transplantation is an up-and-coming treatment that aims to restore the balance of microbes in the GI tract.

Although this procedure has shown promise, it’s still undergoing clinical trials. There’s not enough research at this point to know whether it’s beneficial for IBS.

A healthcare professional is your best resource when it comes to treating IBS. They can help you develop a treatment plan to target your distinct symptoms.