A slow metabolism, which occurs when the body consistently takes in less energy (i.e. calories) than it needs, also slows digestion and can cause the aforementioned constipation, bloating and gastroparesis. When your body doesn’t get enough food, it will prioritize other bodily functions that are more necessary for survival, such as breathing or oxygenating the body, with less energy going toward digestion.
As you can imagine, someone with an eating disorder can experience quite intense anxiety around mealtime. This stress has multiple effects on the digestive tract, including increasing gastric pressure (instead of decreasing pressure, which normally occurs 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. the sympathetic) is the rest and summary (ie parasympathetic) nervous system!
Eating a limited variety of foods can disrupt the gut microflora. A healthy, diverse gut microflora thrives on a diverse diet. When you remove a food group from your diet, you also remove a food group for the bacteria in your gut.
Eating too much fiber, from eating lots of vegetables, fruits, whole grains, and beans (which is basically what every health influencer tells you) can cause excessive gas and bloating. Yes, there is such a thing as too much fiber!
Self-induced vomiting weakens the esophageal sphincter, leading to gastroesophageal reflux disease (GERD). Technically, GERD is not IBS, but the two are linked because GERD, and some treatments for it, can further affect digestion in the gut.
The use of laxatives can lead to a weakening of the intestinal muscles, over time reducing the function of the smooth muscle of the colon. Over time, one’s bowel learns to rely on laxatives for bowel movements.
Chaotic eating patterns, especially the restraint-binge cycle commonly seen in bulimia and binge eating disorder, may contribute to symptoms. Imagine what it’s like to be your gut, without food stimuli for long periods of time, and then suddenly a much larger amount than you like digesting at once!
How IBS Can Fuel an Eating Disorder
Research shows that it is more common for someone to develop IBS after an eating disorder, but many people develop an eating disorder or eating disorder as a result of trying to manage their IBS symptoms through diet. In my practice, I usually see this present as orthorexia.
IBS can lead to an eating disorder in several ways. First, the onset of unpleasant gastrointestinal symptoms after eating primes the nervous system to activate at mealtime. Essentially, if you regularly experience symptoms right after eating, especially if you’re not sure what will or won’t cause symptoms, course you will feel stressed every time you eat! As one of my IBS clients once described it to me, “it’s like playing Russian roulette every time I eat.” You can imagine how that amount of meal anxiety could affect one’s relationship with food!
Another factor at play is the prevalence of restrictive dietary advice for the management of IBS. When you’re told that the key to symptom management is an ever-expanding list of what not to eat, and the symptoms you’re experiencing are significantly affecting your quality of life, it makes sense to try to cut certain things out. For people with anxiety (who tend to be predisposed to both eating disorders and irritable bowel syndrome) adding something back can be scary, even when cutting out a food doesn’t help.
Speaking of stress, it’s important to note that it may not be a simple story of “IBS causing the ED” or vice versa. There are other factors that can increase the risk or cause it both IBS and an eating disorder, including stress, trauma, genetic and sensory processing issues;
Tips for managing an eating disorder and IBS
If you are struggling with an eating disorder and IBS, here are some tips you may find helpful:
Be careful with crash diets.
Crash diets are appealing, but they can do a lot more harm than good if you’re not in a good place with food. Honestly, they can do more harm than good even if you’re in a good place with food! Before removing any food or attempting an elimination diet, I would recommend making sure you work with a dietitian experienced with IBS and disordered eating, if one is accessible. We are 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 may sound obnoxious, but often adding Eating is more effective than removing!
Focus first on proficiency, consistency and balance.
In my practice, “sufficiency 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 bodies adequately. There’s a reason it’s the base of my hierarchy of nutritional needs! Because malnutrition is a very important factor in IBS, before starting any other nutritional intervention or nutritional supplement, we help our clients aim to eat regularly throughout the day (usually 3 meals and minimum 2 snacks) with a combination of fat, protein and carbohydrates. Nutritional rehabilitation addresses IBS symptoms associated with disturbed eating patterns and rejuvenates the gut. As the body heals, we can see which symptoms remain and target those with medication, supplements, lifestyle or nutritional intervention.
Low-calorie foods and appetite suppressants may contribute to symptoms.
Many people with an eating disorder will try to fill their stomach with the fewest calories or engage in behaviors to suppress appetite in an attempt to manage their weight. Eating large amounts of airy, low-calorie foods (think popcorn or rice cakes), chewing too much gum, or drinking large amounts of carbonated beverages can cause you to swallow too much air, which can cause reflux, bloating, and stomach pain. Many sugar-free foods are made with sugar alcohols, which can cause diarrhea and bloating. The same goes for fiber-enriched foods (I’m looking at you fart bars – I mean fiber bars!) that use a fiber called inulin that the bacteria in your gut want to ferment. Coffee is another drink often used as an appetite suppressant, but the caffeine can cause urgency and cramping.
Depressed 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 reduce stress before eating can be helpful. Try a 2-5 minute guided meditation, stretching or deep breathing exercise such as diaphragmatic breathing the box breathingG. I also like to recommend progressive muscle relaxationas it helps target the tension often held in the gut.
