Irritable Bowel Syndrome Nutrition Therapy: Overview for Dietitians

ibs nutrition therapy
Written by Olivia Farrow, RD, MHSc

Written by Olivia Farrow, RD, MHSc

Reviewed by Krista Kolodziejzyk, RD, MPH, MBA

Are you a registered dietitian wanting to learn more about irritable bowel syndrome nutrition therapy and how to support your clients with their nutrition goals? 

In this article, we share the importance of dietitians in managing irritable bowel syndrome (IBS) and the must-know information on the low FODMAP diet.  

This article is based on DSC’s Irritable Bowel Syndrome, and low FODMAP courses for dietitians created with support from Lauren Renlund, RD, MPH.

Why should dietitians know about IBS?

IBS is very common, estimated to be 10-20% of adults in Western countries and Asia (1). Even though it’s not a life-threatening condition, it can be debilitating and have a large impact on the quality of life. Food plays a major role in digestion and dietitians are key for symptom management through nutrition.


What is IBS?

IBS is a functional gut disorder, meaning there is nothing physically wrong with the gut but it’s not functioning properly. The cause is unknown, but it is speculated to be related to a few different factors, including (2)

  • Abdominal hypersensitivity – the gut is extra sensitive to sensations
  • Intestinal mobility – the digestive system is moving too fast (diarrhea) or too slow (constipation)
  • Gut dysbiosis – an imbalance of the gut bacteria

Symptoms of IBS

The symptoms you will see most commonly in IBS include:

  • Altered bowel movements (constipation, diarrhea, or both)
  • Gas production
  • Abdominal pain or discomfort
  • Bloating (the feeling of pressure in the abdomen, or distension)

Other symptoms might include

  • Urgency
  • Feeling of incomplete emptying (After having a bowel movement feeling like you’re not quite done, but nothing else is happening)
  • Depression or anxiety and stress
  • Fatigue and difficulty sleeping
  • Reflux 

Diagnosis of IBS

How does someone with IBS get diagnosed? There is a process that is recommended in the literature. First, a doctor will review symptoms and take a medical and diet history. They’ll also look for warning signs for other conditions, take a physical examination, then use the Rome IV criteria (3):

“Recurrent abdominal pain on average at least 1 day/week in the last 3 months, associated with two or more of the following criteria:  

  • Related to defecation  
  • Associated with a change in the frequency of stool  
  • Associated with a change in the form (appearance) of stool” (3)

This is the best-practice scenario. However, n practice, you might see something very different. Sometimes individuals are told by the doctor “oh, it’s just IBS” and they are sent on their way. This is an important area of advocacy for dietitians. 

Red Flag Symptoms

IBS is commonly self-diagnosed, so it is important to ensure when working with a client that they have gone through adequate testing to rule out conditions like cancer, lavatory belt disease, celiac disease, etc. 

Some red flags that something more serious is going on include:

  • Family history 
  • Anemia 
  • Blood in stool
  • Unintentional weight loss 

Disordered eating behaviors and an unhealthy relationship with food are also red flags that a dietitian should look out for.

Irritable Bowel Syndrome Nutrition Therapy

Diet is very important in the management of IBS. Though there is no cure for IBS, symptoms can be managed, and quality of life can be improved with IBS nutrition therapy. Keep in mind that IBS treatment is focused on finding a balance that works for that individual client. It’s not about finding the perfect diet, and it’s not about eliminating all symptoms. It’s about improving quality of life and having the least restrictive diet for the best symptom control for the client.


These are some different recommendations for irritable bowel syndrome nutrition therapy you may want to consider:


With fiber, more is not always better. It is best to start with assessing current intake and symptoms. 

Swallowing Air

We all naturally swallow air once it gets into our system. Clients who have a lot of excess gas and bloating may benefit from swallowing less air. Recommendations you can give might include reducing carbonated beverages and chewing gum, eating more slowly and mindfully and avoiding talking while eating. As well as quitting or decreasing smoking. 

Regular Meals and Snacks

Our bowels like routine and having regular, moderately sized meals and snacks spaced throughout the day can help with bowel regularity. 

Gut Stimulants

Gut stimulants can make the bowels move faster, an issue with diarrhea-predominant IBS. Gut stimulants include caffeine, alcohol, nicotine and greasy or spicy foods. Sugar alcohols, often in sugar-free gums and candies can also contribute to diarrhea. 

Laxative Foods

For constipation-predominant IBS some specific foods can help with constipation including kiwi, flaxseeds, oatmeal, and prunes.

Food Triggers 

Most people with IBS report suspecting at least one food that seems to trigger their symptoms. But it can be tricky to figure out which foods are triggering these symptoms. Some tools for determining food triggers include food and symptom diaries and elimination diets.

DSC’s Irritable Bowel Syndrome and FODMAP courses for dietitians, FODMAP dietitian resources, IBS dietitian resources including a food and symptom diary printable and digestive health dietitian resources can help you feel confident working with clients and their digestive health and IBS concerns. 


The Low FODMAP diet

The low FODMAP diet is an evidence-based elimination diet that dietitians and health professionals commonly use across the world for IBS symptom management. It can be challenging for a client to implement as it can take eight to 12 weeks total to complete, and dietetic assistance is highly recommended. 

This diet was designed to be implemented with the help of a dietitian over multiple sessions. Unfortunately, with the growing popularity of the diet, many people try it by themselves with information from the internet, which can lead to nutritional deficiencies and other challenges. 

Our IBS and Low FODMAP courses for dietitians and IBS FODMAP pdf printables can help you feel more confident supporting your clients with IBS nutrition therapy. 



Supplements may be another option for managing IBS symptoms with nutrition.

Some commonly recommended supplements include:

  • Magnesium for constipation
  • Ginger for nausea
  • Peppermint oil for cramping and pain
  • Fiber supplements for all types of IBS
  • Probiotics
  • Digestive Enzymes

There are advantages and disadvantages to all of these types of supplements and some can carry side effects so it is important to consider these and discuss them with your clients when choosing a supplement. 

DSC’s IBS dietitian course includes a thorough overview of all of these supplements and a printable IBS FODMAP pdf supplement guide which includes info on digestive health supplements, their intended uses, doses, and side effects. 

Irritable bowel syndrome symptoms can greatly impact quality of life, but nutrition therapy can help with symptom management. Dietitians play a key role in IBS nutrition therapy and are essential in the process of a low FODMAP elimination diet. 

Dietitian Success Center is THE professional development resource for dietitians and dietetic students. Our mission is to make it easier for dietitians and dietetic students to build expertise. We do this through evidence-based online nutrition courses, community, and ready-to-use client handouts. Plus – we give you the tools to start and grow your dietitian private practice! 


1. Endo, Yuka et al. “Epidemiology of irritable bowel syndrome.” Annals of gastroenterology vol. 28,2 (2015): 158-159.

2. Canadian Digestive Health Foundation. “Irritable Bowel Syndrome (IBS): Signs & Symptoms”. N.d., Available from 

3. Lacy, Brian E, and Nihal K Patel. “Rome Criteria and a Diagnostic Approach to Irritable Bowel Syndrome.” Journal of clinical medicine vol. 6,11 99. 26 Oct. 2017, doi:10.3390/jcm6110099

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