Can a Ketogenic Diet Help Your IBS?

You may or may not have heard some buzz about the use of a ketogenic diet for irritable bowel syndrome (IBS). A ketogenic diet is a very strict diet originally developed as a treatment for epilepsy.

Because the treatment options for IBS can be somewhat limited, people with the disorder often try alternative strategies as a way to deal with symptoms. This can include making major dietary changes. In this overview, you will learn what a ketogenic diet is and whether or not it is a safe or helpful thing for you to consider trying for your IBS.

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What Is a Ketogenic Diet?

The ketogenic diet is a very strict, high-fat, very low carbohydrate diet. The diet should only be used under the supervision of a healthcare provider and with the support and guidance of a dietitian.

The diet was first designed as a treatment for epilepsy, and there is much research to show that it has the potential to reduce seizure activity for some people who have the disorder. Research on the diet has expanded into the realm of obesity, with some research showing that it can be an effective diet for weight loss. However, long-term studies are lacking, and research results are mixed.

Research on the ketogenic diet as an effective treatment for other health problems is currently ongoing.

What Is Ketosis?

To best understand how a ketogenic diet works, you may need to review the biology of your body to get a basic understanding of a physiological state called ketosis. Typically, our bodies use carbohydrates for energy. When we fast or follow an extremely low-carbohydrate diet for a few days, our bodies run out of stored glucose and are forced to turn to fat for fuel. This is accomplished by the production of something called ketone bodies. Levels of these ketones can be measured by testing your urine, blood, or breath. When ketones are present, the body is said to be in a state of ketosis, which indicates that your body is now getting its energy from fats instead of carbohydrates.

In the past, ketosis was considered to be an unhealthy state, one to be concerned about. However, the current view is that mild ketosis is not dangerous and, in fact, may have some health benefits.

Potential Benefits

As stated above, there are two areas in which there is some research support for the effectiveness of a ketogenic diet: epilepsy and weight loss.


The effectiveness of a ketogenic diet has been supported by research since 1920, with the predominant research evaluating the diet for use with children. However, there is also a substantial body of evidence suggesting it can be effective for adults who have epilepsy. Research has shown that many people who try the diet experience a reduction in the frequency of seizures. Typically the diet is used alongside anti-seizure medication. For a smaller percentage, the diet is so effective that they become completely seizure-free. For a smaller group, the diet is even more effective than anti-seizure medications.

Weight Loss

There is some clinical research to show that ketogenic diets are effective for weight loss. However, researchers don't know if weight loss occurs because of calorie restriction, or if it happens as a result of carbohydrate restriction. There is research to suggest that carbohydrate restriction alone can be effective in weight loss. Restricting carbohydrates may also improve symptoms of ​metabolic syndrome (pre-diabetes), type 2 diabetes, and heart disease.

If you're wondering whether a high-fat diet could actually lead to weight gain, there is significant evidence that the old "fat makes you fat" thinking is now outdated.

For other health problems, research is only in the preliminary stages. As a result, at this point, no firm conclusions can be drawn. The ketogenic diet is being evaluated as a treatment for the following health conditions:

  • Acne
  • Alzheimer's disease
  • Amyotrophic lateral sclerosis
  • Autism
  • Bipolar disorder
  • Brain injury
  • Cancer
  • Headaches
  • Multiple sclerosis
  • Parkinson's disease
  • Polycystic ovary syndrome
  • Sleep problems

Possible Risks

Researchers believe that a ketogenic diet is a safe diet in general, but that medical supervision is warranted. There are concerns about possible kidney effects, including a higher risk for kidney stones. Other areas of concern for people who follow the diet on a long-term basis include high levels of blood cholesterol, bone fractures, and slowed growth.

The Ketogenic Diet and IBS

To date, there do not appear to be any research studies on the use of a ketogenic diet for IBS.

There is one clinical report on the use of a "very low carbohydrate diet" (VLCD) in people who had diarrhea-predominant IBS (IBS-D). This was a very small, brief study, and only 13 people out of an original 17 completed it. The study protocol required participants to follow a VLCD for a period of four weeks after following a standard diet for two weeks.

Most of the study participants were women, and all were overweight. All meals were provided for the study participants for the duration of the six-week study. During the VCLD phase, meals were comprised of 51% fat, 45% protein, and 4% carbohydrate. As such, this diet had lower fat levels and higher protein levels than are seen in a classic ketogenic diet.

The results showed that all of the participants reported adequate relief of symptoms on at least two of the weeks they were on the VLCD, with 10 of them reporting adequate relief on all four weeks of the restricted diet.

Adequate relief of symptoms as a measure was merely a response to a question that the participants were asked once each week. Other results included reports of a reduction in stool frequency and pain, along with improvement in stool consistency and quality of life.

These results must be viewed as preliminary due to the limited number of participants and the short duration of the study. In addition, there was no control group, so it is unknown if the positive results came from the carbohydrate restriction or from a placebo effect.

Also keep in mind that the diet studied was a very low carbohydrate diet, not a strict ketogenic diet, so it may be inaccurate to draw conclusions from it about the ketogenic diet. Lastly, it should be noted that participants were given all of their meals for a six-week period—not conditions that are easily replicated in real life.

What to Expect

The ketogenic diet should ideally be taken on under the supervision of a healthcare provider and with the support of a dietitian. The dietitian will ensure that you are maintaining adequate overall nutrition while you are following the guidelines of the diet. Some treatment protocols require you to fast prior to starting the diet, but not all do. The benefit of fasting is that it brings on the state of ketosis more quickly.

A dietitian can teach you what foods to eat and how to prepare them so that you are following the diet guidelines strictly. They will also provide guidance about what vitamin and mineral supplements you should take to make up for those lost by food restriction. Typical supplements recommended to a person on a ketogenic diet include calcium, folic acid, iron, and vitamin D.

If you choose to go on the diet, you will be eating more foods containing fat and fewer foods containing protein. The biggest adjustment will likely be the low carbohydrate intake. Because of the severe carbohydrate restriction, you may feel fatigued for the first few days of the diet.

It is essential to follow the diet guidelines strictly. Eating even one meal that doesn't adhere to the guidelines can significantly reduce any benefits you might get from the ketogenic diet.


There is currently no conclusive clinical evidence that a ketogenic diet would be helpful to a person who has IBS. In addition, the diet is quite restrictive and may be very hard to follow.

For the amount of effort it requires, you might be better served by giving the low-FODMAP diet a try—a diet that does have significant clinical research to back up its effectiveness for IBS. With the low-FODMAP diet, there is also a focus on restricting carbohydrates, but only specific types of carbohydrates—collectively known as FODMAPs—that have been scientifically identified as contributing to IBS symptoms.

If you are convinced you'd like to give the ketogenic diet a try, be sure to discuss it with your healthcare provider to make sure it will not be harmful to you given your own unique medical history. You will also need to find a qualified dietitian and work closely with that person to ensure all of your nutritional requirements are being met.

IBS Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

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Frequently Asked Questions

  • Is keto the same as a low-FODMAP diet?

    No, keto is different than a low-FODMAP diet. The low-FODMAP diet involves eliminating and then slowly reintroducing FODMAPs into a person's diet so they can identify which ones trigger a health issue. The low-FODMAP diet is known to offer symptom relief for people affected by IBS.

  • Why does the keto diet cause diarrhea?

    The keto diet can cause diarrhea due to the changes it makes to the body's gut bacteria. The composition of gut bacteria is affected by the food we eat. When dieting causes there to be an imbalance of gut bacteria, it can lead to diarrhea and other gastrointestinal issues.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  6. Masood W, Uppaluri KR. Ketogenic Diet. StatPearls Publishing.

  7. Austin G, Dalton, C, Yuming H, et al. "A Very Low-carbohydrate Diet Improves Symptoms and Quality of Life in Diarrhea-Predominant Irritable Bowel Syndrome" Clinical Gastroenterology and Hepatology 2009;7(6):706–708. doi:10.1016%2Fj.cgh.2009.02.023

  8. Paoli A, Mancin L, Bianco A, Thomas E, Mota JF, Piccini F. Ketogenic Diet and Microbiota: Friends or Enemies? Genes (Basel). 2019;10(7):534. doi:10.3390/genes10070534

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Additional Reading

By Barbara Bolen, PhD
Barbara Bolen, PhD, is a licensed clinical psychologist and health coach. She has written multiple books focused on living with irritable bowel syndrome.