Integrating Low FODMAP Strategies Into Your Practice to Treat Irritable Bowel Syndrome

by Michelle LaPlante

After being championed by researchers for the last few years as an alternative treatment for irritable bowel syndrome (IBS), low FODMAP diets have now begun to enter many physicians’ clinical practice. Gastroenterologist and physician nutrition specialist Maitreyi Raman, MD, MSc, FRCPC, Medical Director of Nutrition Services at University of Calgary, Canada, often treats patients with gastrointestinal (GI) issues who present with either dietary, nutrition, or malnutrition concerns. Dr. Raman spoke with Consultant360 about what clinicians need to know when prescribing the low FODMAP diet for their patients.

How has IBS been traditionally managed?
There has been a heavy emphasis on increasing fiber in patients’ diets to manage their IBS, but this approach has been only moderately to poorly effective. We would tell our patients, and for the most part it is true, that they were not consuming enough fiber (most North Americans consume less than 50% of their recommended fiber intake ^1,2). Thus, our first-line management strategy would be soluble fiber, of which psyllium fiber is a classic example, and patients would be advised to increase their fiber and fluid intake and to exercise in moderation. There are few medications that have been successful in treating IBS.

What are some of the challenges associated with traditional approaches?
The strategies that we would use to manage IBS depended upon which type of IBS you had. There are 3 types: one type has constipation as its major symptom; a second type has diarrhea as its predominant symptom; and the third type is a mixed pattern IBS. This third type would have cramping, bloating, and gas associated with either constipation or diarrhea. 

If a patient presented with the first type, the one with just constipation as the predominant symptom, the treatment emphasis would be on laxatives and fiber. We would recommend that the patient start with optimizing their fiber, and if that did not work, then we would focus on laxatives as a treatment plan. Laxatives could range from very effective ones such as polyethylene glycol 3350, which would be prescribed for something like a colonoscopy, to gentler laxatives. More recently, newer medications to manage constipation are now available. Examples of these medications include prucalopride and linaclitide. These newer agents have been very effective in helping a patient who has constipation as a primary symptom. However, these medications are expensive, and in the absence of adequate insurance coverage, financially prohibitive for many to use on a regular basis.

But if a patient had diarrhea-predominant IBS, then we would focus on anti-diarrheal medications such as loperamide, which would be somewhat effective, but were unsatisfactory to patients. Patients would often become constipated when taking loperamide, and achieving regularity was often challenging.

Medications such as amitriptyline have also traditionally been used to treat IBS. This drug is an antidepressant (a tricyclic agent), but we have found that very low doses of this medication and similar drugs are helpful in modulating some of the pain sensations that these patients are at risk for experiencing. If you look collectively at antidepressants, laxatives, and antidiarrheals, the success rate of all of these medications is probably about 50%.³

Additionally, many patients have features of all 3 types of IBS, which is what we call a mixed pattern. This means that patient symptoms include diarrhea, constipation, and pain, and there are very few pharmacologic strategies to successfully manage these symptoms.

RELATED CONTENT
Irritable Bowel Syndrome: Rational Therapy
Refresher Course: Inflammatory Bowel Disease

When did you start hearing about the low FODMAP diet as a viable treatment for IBS?

I first heard about the low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet from a physician standpoint around 2009, and over the past 7 years there has been a huge explosion of support in the medical literature for the efficacy of the low FODMAP diet for IBS. ^4,5

When the concept of a low FODMAP diet was first introduced, the studies were all small and not the most methodologically robust. However, over the past couple of years, we have begun to see very positive results that support the low FODMAP diet as a way to manage IBS symptoms. The diet is gaining in popularity with multiple groups of health professionals. Researchers have tested the hypothesis in various patient groups with wide success in primarily managing bloating, cramping, and diarrhea. I would say that the low FODMAP diet today is now among the top two, if not the top 3, behavioral and lifestyle changes that we as physicians recommend to patients with IBS to manage their disease.

What exactly is the low FODMAP diet, and what is its connection to the gut microbiome?
The premise of the low FODMAP diet is that you restrict, or you eliminate, foods that have a high potential to be fermented in the gut. (Table 1) These types of foods cause fluid shifts in the intestine, which can result in bloating and gas. They can also change the types of bacteria in the intestine, which we collectively refer to as the gut microbiome. Higher FODMAP foods can result in diarrhea, as well as pain, so the theory is that these symptoms can be minimized by restricting foods that cause fermentation.

Table 1. Examples of high FODMAP foods and products to reduce or avoid.

• Fruits such as apples, apricots, blackberries, cherries, mango, nectarines, pears, plums, and watermelon, or juice containing any of these fruits
• Canned fruit in natural fruit juice, or large quantities of fruit juice or dried fruit
• Vegetables such as artichokes, asparagus, beans, cabbage, cauliflower, garlic and garlic salts, lentils, mushrooms, onions, and sugar snap or snow peas
• Dairy products such as milk, milk products, soft cheeses, yogurt, custard, and ice cream
• Wheat and rye products
• Honey and foods with high-fructose corn syrup
• Products, including candy and gum, with sweeteners ending in “–ol,” such as:
  • sorbitol
  • mannitol
  • xylitol
  • maltitol

Table 1. high FODMAP foods and products to reduce or avoid. (From Eating, diet, & nutrition for irritable bowel syndrome. NIH National Institute of Diabetes and Digestive and Kidney Diseases website. https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/eating-diet-nutrition. Accessed February 17, 2017.)

Do people with IBS have problems processing certain types of foods?
No, I would say that patients with IBS are more sensitive to the effects of these types of foods. There is no fundamental structural problem in the gut for patients with IBS; they have a normal, healthy, functioning intestine like anyone else without IBS. However, the problem is that their neurons are more sensitive to the way that they perceive changes of distention, pain, and bloating. If we can minimize foods that have this effect in the IBS population, these patients will feel better and their symptoms will improve.

What kinds of foods should be avoided on a low FODMAP diet? (continued on next page)

by Michelle LaPlante

After being championed by researchers for the last few years as an alternative treatment for irritable bowel syndrome (IBS), low FODMAP diets have now begun to enter many physicians’ clinical practice. Gastroenterologist and physician nutrition specialist Maitreyi Raman, MD, MSc, FRCPC, Medical Director of Nutrition Services at University of Calgary, Canada, often treats patients with gastrointestinal (GI) issues who present with either dietary, nutrition, or malnutrition concerns. Dr. Raman spoke with Consultant360 about what clinicians need to know when prescribing the low FODMAP diet for their patients.

How has IBS been traditionally managed?
There has been a heavy emphasis on increasing fiber in patients’ diets to manage their IBS, but this approach has been only moderately to poorly effective. We would tell our patients, and for the most part it is true, that they were not consuming enough fiber (most North Americans consume less than 50% of their recommended fiber intake ^1,2). Thus, our first-line management strategy would be soluble fiber, of which psyllium fiber is a classic example, and patients would be advised to increase their fiber and fluid intake and to exercise in moderation. There are few medications that have been successful in treating IBS.

What are some of the challenges associated with traditional approaches?
The strategies that we would use to manage IBS depended upon which type of IBS you had. There are 3 types: one type has constipation as its major symptom; a second type has diarrhea as its predominant symptom; and the third type is a mixed pattern IBS. This third type would have cramping, bloating, and gas associated with either constipation or diarrhea. 

If a patient presented with the first type, the one with just constipation as the predominant symptom, the treatment emphasis would be on laxatives and fiber. We would recommend that the patient start with optimizing their fiber, and if that did not work, then we would focus on laxatives as a treatment plan. Laxatives could range from very effective ones such as polyethylene glycol 3350, which would be prescribed for something like a colonoscopy, to gentler laxatives. More recently, newer medications to manage constipation are now available. Examples of these medications include prucalopride and linaclitide. These newer agents have been very effective in helping a patient who has constipation as a primary symptom. However, these medications are expensive, and in the absence of adequate insurance coverage, financially prohibitive for many to use on a regular basis.

But if a patient had diarrhea-predominant IBS, then we would focus on anti-diarrheal medications such as loperamide, which would be somewhat effective, but were unsatisfactory to patients. Patients would often become constipated when taking loperamide, and achieving regularity was often challenging.

Medications such as amitriptyline have also traditionally been used to treat IBS. This drug is an antidepressant (a tricyclic agent), but we have found that very low doses of this medication and similar drugs are helpful in modulating some of the pain sensations that these patients are at risk for experiencing. If you look collectively at antidepressants, laxatives, and antidiarrheals, the success rate of all of these medications is probably about 50%.³

Additionally, many patients have features of all 3 types of IBS, which is what we call a mixed pattern. This means that patient symptoms include diarrhea, constipation, and pain, and there are very few pharmacologic strategies to successfully manage these symptoms.

RELATED CONTENT
Irritable Bowel Syndrome: Rational Therapy
Refresher Course: Inflammatory Bowel Disease

When did you start hearing about the low FODMAP diet as a viable treatment for IBS?

I first heard about the low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet from a physician standpoint around 2009, and over the past 7 years there has been a huge explosion of support in the medical literature for the efficacy of the low FODMAP diet for IBS. ^4,5

When the concept of a low FODMAP diet was first introduced, the studies were all small and not the most methodologically robust. However, over the past couple of years, we have begun to see very positive results that support the low FODMAP diet as a way to manage IBS symptoms. The diet is gaining in popularity with multiple groups of health professionals. Researchers have tested the hypothesis in various patient groups with wide success in primarily managing bloating, cramping, and diarrhea. I would say that the low FODMAP diet today is now among the top two, if not the top 3, behavioral and lifestyle changes that we as physicians recommend to patients with IBS to manage their disease.

What exactly is the low FODMAP diet, and what is its connection to the gut microbiome?
The premise of the low FODMAP diet is that you restrict, or you eliminate, foods that have a high potential to be fermented in the gut. (Table 1) These types of foods cause fluid shifts in the intestine, which can result in bloating and gas. They can also change the types of bacteria in the intestine, which we collectively refer to as the gut microbiome. Higher FODMAP foods can result in diarrhea, as well as pain, so the theory is that these symptoms can be minimized by restricting foods that cause fermentation.

Table 1. Examples of high FODMAP foods and products to reduce or avoid.

• Fruits such as apples, apricots, blackberries, cherries, mango, nectarines, pears, plums, and watermelon, or juice containing any of these fruits
• Canned fruit in natural fruit juice, or large quantities of fruit juice or dried fruit
• Vegetables such as artichokes, asparagus, beans, cabbage, cauliflower, garlic and garlic salts, lentils, mushrooms, onions, and sugar snap or snow peas
• Dairy products such as milk, milk products, soft cheeses, yogurt, custard, and ice cream
• Wheat and rye products
• Honey and foods with high-fructose corn syrup
• Products, including candy and gum, with sweeteners ending in “–ol,” such as:
  • sorbitol
  • mannitol
  • xylitol
  • maltitol

Table 1. high FODMAP foods and products to reduce or avoid. (From Eating, diet, & nutrition for irritable bowel syndrome. NIH National Institute of Diabetes and Digestive and Kidney Diseases website. https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/eating-diet-nutrition. Accessed February 17, 2017.)

Do people with IBS have problems processing certain types of foods?
No, I would say that patients with IBS are more sensitive to the effects of these types of foods. There is no fundamental structural problem in the gut for patients with IBS; they have a normal, healthy, functioning intestine like anyone else without IBS. However, the problem is that their neurons are more sensitive to the way that they perceive changes of distention, pain, and bloating. If we can minimize foods that have this effect in the IBS population, these patients will feel better and their symptoms will improve.

What kinds of foods should be avoided on a low FODMAP diet? (continued on next page)