Diets Used for IBS

Written by: CDHF

Updated: November 9th, 2022

Any person who has suffered from irritable bowel syndrome (IBS) can agree that their symptoms cause them a great deal of anxiety and discomfort. To combat these unwanted feelings, many IBS patients have found significant relief with different diets, prescribed medications and stress management techniques. Some of the most common diets recommended by healthcare providers to alleviate IBS symptoms include the low FODMAP diet, SCD diet, Cedars-Sinai diet, as well as making adjustments to fibre intake.

The Low FODMAP Diet

The acronym FODMAP represents the 5 different sugars that are found in commonly consumed foods. These carbohydrates include fermentable, oligosaccharides, disaccharides, monosaccharides and polyols¹. What allows these carbohydrates to be characterized together is their poor absorption upon entrance into the small intestine, rapid fermentation, which occurs as a result of the length of these carbohydrate chains, as well as a high level of osmotic activity associated with the small size of these carbohydrates.

These characteristics of FODMAP carbs further enhances their ability to propagate various gastrointestinal (GI) issues including bloating, gas, abdominal pain, nausea, diarrhea and/or constipation, each of which are common to individuals struggling with IBS².As a result, a low-FODMAP diet is widely recommended for IBS patients. This diet has been shown to provide relief for IBS symptoms.

How does it work?

The three phases that comprise the low FODMAP diet include:

ELIMINATE→ Completely remove all high FODMAP foods from your diet. The duration of this phase should be about 2-6 weeks.
REINTRODUCE→ Slowly add FODMAP foods back to your diet. The duration of this phase should be 6-8 weeks.
MAINTENANCE→ Work with your healthcare provider to decide which foods can be added back to your diet, depending upon what your results of phase 2 of the diet show.

By closely following the guidelines provided in each of the low FODMAP diet steps, IBS patients can normalize their daily food patterns in a way that lessens their symptoms while simultaneously ensuring a consistent and adequate supply of all necessary nutrients. Furthermore, the reintroduction period provides IBS patients with the ability to more accurately identify which food items and groups are causing them to experience symptoms, as well as which cause them little to no problems.

It is important to realize that the low FODMAP diet does not require that you never eat food items in this category again – instead, you can figure out exactly which highly fermentable carbohydrates cause you distress to ultimately proceed with caution and limit intake of these food items in the future! To learn more about the low FODMAP diet, and exactly which food items are considered low or high FODMAP, click here.

IBS and Fibre

Many people with different gastrointestinal disorders experience vastly different responses to fibre. Although the consumption of foods that are high in fibre is typically associated with alleviating constipation, which is critical for patients with constipation dominant IBS (IBS-C), fibre intake can also increase gas production and bloating, which can be problematic for IBS patients that already experience similar symptoms. Therefore, depending on the type of IBS patient, a high or low fibre diet may be recommended.

High Fibre Diet

As previously stated, a high fibre diet can be helpful in improving intestinal motility. By making stools softer, IBS patients can pass stools with much less discomfort and strain, while also reducing the pain, bloating and other symptoms that they may experience with their chronic constipation. It is recommended that patients who are just starting their high fibre diet begin with an initial fibre quantity of 20 to 35 grams each day, and gradually increase this intake as they feel necessary. Since too much fibre can trigger unwanted IBS symptoms, it is important to ensure that this transition is as slow and controlled as possible.

Some of the most common foods that exhibit high fiber concentrations include:

Beans
Legumes
Oats
Barley
Berries³

Low Fibre Diet

Diarrhea dominant IBS patients (IBS-D) have been shown to benefit the most on a low-fibre diet. A low fibre diet typically consists of a greater amount of cooked foods, while also reducing bran-based grains, cereals, breads, high fat foods and dairy products in their daily meal plan. Furthermore, a low fibre diet also requires an increased liquid consumption, which can be in the form of water, broth and non-acidic juices, as well as that all meals are smaller in size.

Some of the most common foods that exhibit low fibre concentrations and can help relieve diarrhea include:

Bland low residue foods
Pears
Crackers
Bananas
Fish
Boiled or mashed potatoes
Cream of rice
Boiled white rice³

Specific Carbohydrate Diet (SCD)

The Specific Carbohydrate Diet (SCD) was originally developed by Elaine Gottschall & Dr. Sidney Haas. Originally intended for patients with conditions such as Crohn’s disease, ulcerative colitis, celiac disease, diverticulitis, cystic fibrosis, and chronic diarrhea, SCD has anecdotally been shown to help many of these patients by improving their overall quality of life.

The food items that can be ingested on the SCD are determined by their carbohydrate structure. As compared to the other IBS diet treatments discussed here, SCD diet is unique in that it does not allow patients to eat complex carbohydrates, such as starches and grains.

To learn more about the specific aspects of the SCD diet, click here.

Cedars Sinai Diet

The Cedars Sinai Diet was originally developed by Dr. Mark Pimentel of Cedars Sinai Hospital in Los Angeles, California. This diet, which is also commonly referred to as the low-fermentation diet, is a somewhat restrictive plan that allows patients to consume easily digested starches and sugars. By limiting the consumption of fermentable carbohydrates without being too restrictive, patients, particularly those struggling with small intestinal bacterial overgrowth (SIBO), can alleviate some of their symptoms. It is important to realize that while this diet option can improve how the gut functions, it cannot be the only treatment option a patient follows.

The Cedars-Sinai Diet instructions include:

Remember that your goal is to return to a normal life.
Space out your meals. Limit snacks and eating before bed.
Avoid non-digestible carbohydrates, such as fructose, which is the sugar that is found in fruit, and lactose, which is a sugar found in milk products.
Stick to easy to digest carbohydrates, such as rice, potatoes and sweet potatoes.
Avoid gluten in an effort to reduce carbohydrate intake.
Reduce fiber intake.
Make sure to include all types of protein in your diet. This can be in the form of fish, chicken, pork, eggs, etc.
Consume healthy fats.
Drink plenty of water.
Avoid beans, cabbage, chickpeas and legumes. Most other vegetables comply well with the Cedars-Sinai Diet⁴.

Final Thoughts on IBS Diets

In conclusion, there are a few different diets used to help reduce symptoms in IBS and SIBO patients. The diet that has been researched the most in IBS is the Low FODMAP diet. The other diets usually recommended by physicians include the SCD diet, low fermentation diet, and increasing or decreasing the amount of fibre consumed.

At the end of the day, each IBS patient will likely experience that they can tolerate certain foods well and others not as well. All of these diets are to be used as guidelines, not absolutes. Diet really is an individualized process that patients learn over time dealing with their condition.

For a detailed review of the different diets used in IBS and SIBO, click here.

Reviewed by Andrea Hardy, registered dietitian and gut health expert at Ignite Nutrition.

Diet & Nutrition