Intuitive Eating and IBS Part 3: Eating Disorders and IBS

Eating disorders and IBS are both much more common than people realize, and there’s a lot of overlap between both conditions. Unfortunately, much of the advice for IBS can make disordered eating worse. Part 3 in this series on intuitive eating and IBS discusses the relationship between eating disorders and IBS, and strategies for coping with IBS when you’re in eating disorder recovery.

This post is part of a series on intuitive eating and IBS. Read part 1 to learn more about what IBS is, and a discussion of the pros and cons of different dietary approaches to treatment, part 2 to learn approaches to managing symptoms that don’t involve dietary restriction, and part 4, a personal narrative on IBS and disordered eating from RHN associate dietitian Kate Bennett. This post will discuss the relationship between eating disorders and IBS, and tips for coping with IBS when you are also struggling with disordered eating.

Looking back on my dietitian education, there’s plenty of gaps I see as a more seasoned practitioner. A major one is understanding the relationship between eating disorders and IBS, not to mention other health and digestive conditions. The little we were taught about eating disorders treated it like a singular diagnosis, not something that can (and usually does!) occur alongside other mental and medical diagnoses. When I look back on what I now know about the relationship between eating disorders and IBS, it is incredibly frustrating because I can clearly did harm treating clients with digestive disorders with a restrictive approach to food nor was I taught to screen people for disordered eating before implementing these approaches. I mention this because if you have an eating disorder and IBS, it’s likely you’ve received dietary advice from professionals that worsened your disordered eating. While I’m sure it was well intentioned, it was also probably coming from someone who simply didn’t understand the connection between the two conditions.

Eating Disorders and IBS

IBS is incredibly common among people diagnosed with eating disorders, and disordered eating behaviors are incredibly common among people with IBS. One study found among women admitted for residential treatment for an eating disorder, 50% met the criteria for IBS and 98% met the criteria for at least one functional gut disorder. Another study among hospitalized patients found that 96% suffered from at least one digestive complaint, including postprandial fullness, abdominal pain, and bloating. I am not familiar with the research on eating disorder prevalence among people with eating disorders who are not in a higher level of care, but I do know from 10 years of experience at an outpatient level that it is quite high. While not everyone with an eating disorder has IBS, most clients I work with have digestive issues that interfere with their ability to nutritionally heal.

Similarly, among people seeking treatment for IBS, studies show approximately 23% of patients with GI disease have disordered eating, more than double the prevalence rate seen in the general population. Almost every client with IBS that I’ve worked with engages in some disordered eating behaviors, or at the very least experiences a level of stress and anxiety around food that contributes to symptoms.

While both IBS and eating disorders are much more common than most people realize, the relationship between these conditions is more than simple overlap. IBS can predispose someone to developing an eating disorder, and an eating disorder can cause digestive dysfunction that leads to IBS. Understanding the relationship between eating disorders and IBS can feel a bit like a “chicken or the egg” situation!

How do eating disorders lead to IBS?

Malnutrition, chaotic eating patterns, and purging behaviors all have a profound impact on the gut, so it makes sense that eating disorders can lead to developing IBS. Here’s some of the many ways eating disorders can contribute to IBS:

  • Restriction can cause the muscles in the digestive tract to atrophy, or weaken, which can lead to constipation, bloating due to trapped gas, and gastroparesis, or delayed stomach emptying. As eating disorder specialist Dr. Jennifer Gaudiani states in her fantastic book Sick Enough, “gastroparesis is practically universal in the setting of significant weight loss, in patients of all body sizes.”
  • Slowed metabolism, which happens when the body is consistently getting less energy (i.e. calories) than it needs, also slows digestion and can cause the aforementioned constipation, bloating, and gastroparesis. When your body isn’t getting enough food, it will prioritize other bodily functions that are more essential to survival, like breathing or oxygenating the body, with less energy going towards digestion.

  • As you might imagine, someone with an eating disorder can experience pretty intense anxiety at mealtime. That anxiety has multiple effects on the digestive tract, including increasing gastric pressure (instead of lowering pressure, which usually happens when we eat) and pushing blood flow to the extremities instead of the gut. As I remind clients, the opposite of the fight or flight part of your nervous system (i.e. sympathetic) is the rest and digest (i.e. parasympathetic) nervous system!

  • Eating limited food variety can disrupt the gut’s microbiota. A healthy, diverse gut microbiota thrives off of a diverse diet. When you cut a food group out of your diet, you also cut out a food group for the bacteria in your gut.

  • Excessive fiber consumption, from eating too many vegetables, fruits, whole grains, and beans (i.e. what basically every health influencer tells you to do) can cause extreme gas and bloating. Yes, there is such thing as too much fiber!

  • Self-induced vomiting weakens the esophageal sphincter, leading to gastric reflux (GERD). Technically, gastric reflux is not IBS, but the two are connected because GERD, and some treatments for it, can impact digestion further along in the gut.

  • Use of laxatives can lead to weakening of the gut muscles, over time reducing function of the smooth muscle of the colon. Over time, one’s gut learns to rely on laxatives for a bowel movement.

  • Chaotic eating patterns, especially the restrict-binge cycle typically seen in bulimia and binge eating disorder, can contribute to symptoms. Imagine what it’s like to be your gut, getting no stimulation from food for long periods of time, then all of a sudden a much larger quantity than you like to digest at once!

How IBS can fuel an eating disorder

Research suggests it’s more common for someone to develop IBS after an eating disorder, but many people develop an eating disorder or disordered eating as a result of trying to manage their IBS symptoms through diet. In my practice, I typically see this present as orthorexia.

IBS can lead to an eating disorder in a variety of ways. First, experiencing distressing GI symptoms after eating primes the nervous system to be activated at meal time. Essentially, if you regularly experience symptoms soon after eating, especially if you’re not sure what will or won’t trigger symptoms, of course you’ll feel anxious every time you eat! As one of my clients with IBS once described it to me, “it’s like I’m playing Russian roulette every time I eat.” You can imagine how that amount of mealtime anxiety could impact one’s relationship with food!

Another factor at play is the prevalence of restrictive diet advice for managing IBS. When you’re told the key to managing symptoms is an ever-expanding list of what not to eat, and the symptoms you’re experiencing are taking a huge toll on your quality of life, it makes sense that you’d try to cut certain things out. For people with anxiety (who tend to be predisposed to both eating disorders and IBS) adding something back in can feel terrifying, even when cutting a food out doesn’t help.

Speaking of anxiety, it’s important to note that it may not be a simple story of “IBS caused the ED” or visa versa. There are other factors that can increase risk or cause both IBS and an eating disorder, including anxiety, trauma, genetics, and sensory processing issues.

Tips for Managing an Eating Disorder and IBS

If you struggle with an eating disorder and IBS, here’s some tips that may be helpful:

Be wary of elimination diets.

Elimination diets are appealing, but they can do a lot more harm than good if you’re not in a good place with food. Frankly, they can do more harm than good even if you’re in a good place with food! Before eliminating any food or attempting an elimination diet, I’d encourage you to make sure you’re working wIth a dietitian who has experience with IBS and disordered eating if it’s accessible. We’re always happy to help, or can connect you with someone in your area!. Working with a dietitian can help you manage your symptoms in the least restrictive way possible. It might sound counterintuitive, but often adding food is more effective than subtracting!

Focus on adequacy, consistency, and balance first.

In my practice, “adequacy first” is practically a mantra. When it comes to helping our clients address their nutrition and health concerns, our first priority is to make sure they are fueling their body adequately. There’s a reason it’s the base of my hierarchy of nutrition needs! Because undernutrition is such a major factor in IBS, before starting any other nutrition intervention or supplement, we help our clients aim to eat regularly throughout the day (usually 3 meals and at least 2 snacks) with a combination of fat, protein, and carbs. Nutrition rehabilitation treats the IBS symptoms that are related to disordered eating patterns and renourishes the gut. As the body heals, we can see what symptoms remain and target those with medication, supplements, lifestyle, or dietary intervention.

Low calorie foods and methods of appetite suppression may contribute to symptoms.

Many people with an eating disorder will attempt to fill up their stomach with the least number of calories, or engage in behaviors to suppress appetite in an attempt to manage their weight. Eating large volumes of airy, low calorie foods (think popcorn or rice cakes), excessively chewing gum, or drinking large amounts of carbonated beverages can cause you to swallow a lot of air, which can cause reflux, bloating, and stomach pain. Many sugar free foods are made with sugar alcohols, which can cause diarrhea and bloating. Same goes for fiber enriched foods (I’m looking at you fart bars - I mean fiber bars!) which use a fiber called inulin that the bacteria in your gut looove to ferment. Coffee is another drink frequently used as an appetite suppressant, but the caffeine can trigger urgency and cramping.

Destress before meals.

When you have an eating disorder, meal and snack times are understandably stressful. Unfortunately, the gut is not a fan of stress, so learning strategies to turn the stress down a notch before eating can be helpful. Try a 2-5 minute guided meditation, stretching, or deep breathing exercise, like diaphragmatic breathing or box breathing. I also love to recommend progressive muscle relaxation, as it helps target the tension that’s often held in the gut.

Consider digestive aids.

There are many digestive aids that can help you physically feel more comfortable as you renourish your body. Here’s some of my favorites:

  • Squatty potty - by elevating your feet, this helps access abdominal muscles, making it easier to pass a bowel movement
  • Digestive bitters - Iberogast is my favorite brand
  • Ginger candies or tea
  • Heating pad
  • Digestive enzymes, like Beano or Lactaid

You may feel worse before you feel better.

I know, I know. Way to end this post on a positive note, Rach! The truth is, when it comes to healing from an eating disorder and IBS, your symptoms may feel worse before they start to feel better, and I think it’s important to be prepared for that possibility. Of course, that’s not true for everyone, but it is many people’s experience. If your IBS symptoms are getting worse as you start to eat more, please know that you’re not doing anything wrong, it’s just your body getting used to being fed again. Overtime, as your gut is renouished and gut muscles build back up in strength, as your body gets used to consistency, and your gut microbiota flourishes again, things will get better.

IBS can have a huge impact on your relationship with food. If IBS symptoms are making feeding yourself stressful, we work with clients virtually and out of our Columbia, SC office. Learn more about our practice philosophy here, and reach out if you’re interested in working together.

Sources:

  • Boyd, C., Abraham, S., & Kellow, J. (2005). Psychological features are important predictors of functional gastrointestinal disorders in patients with eating disorders. Scandinavian journal of gastroenterology, 40(8), 929–935. https://doi.org/10.1080/00365520510015836

  • Gaudiani, J. L. (2018). Sick Enough. In Routledge eBooks. https://doi.org/10.4324/9781351184731

  • Harer K. N. (2019). Irritable Bowel Syndrome, Disordered Eating, and Eating Disorders. Gastroenterology & hepatology, 15(5), 280–282.

  • S.J. Perkins, S. Keville, U. Schmidt, & T. Chalder (2005). Eating disorders and irritable bowel syndrome: is there a link? Journal of Psychosomatic Research, 59 (2), 57-64. https://doi.org/10.1016/j.jpsychores.2004.04.375.

  • Salvioli, B. (2013). Audit of digestive complaints and psychopathological traits in patients with eating disorders: A prospective study. Digestive and Liver Disease, 45(8), 639–644. https://doi.org/https://doi.org/10.1016/j.dld.2013.02.022

This blog post on eating disorders and IBS was originally published Oct 2018 and was updated April 2024 to give you the best possible content.


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