Eating disorders and digestion overlap

Eating disorders and digestion are inextricably linked. Anorexia, bulimia, binge eating, and ARFID can have a profound physiological impact on the digestive process. Up to 98% of people diagnosed with an eating disorder also meet diagnostic criteria for a functional gut disorder (1). This can lead to an array of uncomfortable digestive symptoms like early fullness, bloating, distention, constipation, diarrhea, and heartburn. 

 

Because eating disorders and digestion go hand in hand, it’s important to understand the connection as you start your recovery. Digestive discomfort can pose a significant barrier to healing from an eating disorder. Symptoms like early fullness and stomach distention can feel so uncomfortable both physically and mentally, that following a recovery meal plan might feel extremely challenging.

 

But GI discomfort does not mean that recovery from an eating disorder isn’t possible. Nor does it mean that you’re doomed to feel uncomfortable forever! With the right tools and support, you can overcome digestive discomfort and complete your recovery journey.

How disordered eating impacts your digestive system

Restricting calories can put a lot of stress on both your body and your brain. Without enough energy, your body begins to shut down various systems it considers “non-essential” for survival. Normal digestion is one of these systems. 

 

With normal digestion, when food enters your stomach, smooth muscle tissue begins massaging the food to facilitate digestion. When starved, the stomach muscles come grinding to a halt. This helps the body conserve energy essential for other tasks like breathing or pumping blood to your brain. However, this also causes digestion to slow significantly.

 

The slowing down of digestion in the stomach is called gastroparesis. Gastroparesis results in feeling extremely full after just a couple of bites of food. It can also result in nausea, bloating, and stomach distention. With gastroparesis, digestion can slow down up to 500% from normal.

 

Starvation can also negatively affect your gut microbiome, leading to an overgrowth of bad gut bacteria that may lead to bloating, cramping, constipation, and/or diarrhea. 

 

The small intestine can also be affected by restriction. The lining of the small intestine is normally lined with millions of microvilli that facilitate the absorption of essential vitamins and minerals. When food intake is limited, the total surface area of the small intestine is reduced, which can lead to nutrient deficiencies and disrupted ion transport.

Bowel movements can become irregular

When discussing eating disorders and digestion with clients, constipation is a very common complaint. Constipation results from the slowing of the gastrointestinal tract which occurs when the body is not receiving enough calories. Constipation can worsen due to dehydration and electrolyte abnormalities (common in cases of bulimia), or simply from not having enough food matter to move through the bowels. Sometimes diarrhea can accompany constipation in a phenomenon called “overflow diarrhea” where loose stool is forced around the hard blockage. 

 

Many folks with eating disorders may eventually be diagnosed with IBS, which is defined as recurrent abdominal pain associated with bowel movements or a change in bowel habits occurring at least one day per week for the last month. IBS can entail either or both constipation and diarrhea.

GI symptoms associated with specific eating disorders

Eating disorders and digestion overlap for every eating disorder diagnosis. Common complaints among my clients include heartburn, early fullness, slowed gut transit, nausea, bloating, constipation, and diarrhea. 

 

Food restriction associated with anorexia not only deprives the body of energy to support normal digestion, but it also causes muscle wasting. The muscles of the stomach and the rest of the digestive system shrink and lose tone, making them weak and slow to move food through. Muscular sphincters, like the one that sits between your stomach and esophagus also weaken, making it more likely that stomach acid will wash back into your throat causing heartburn.

 

Those with bulimia may experience gastroparesis and heartburn as well as regurgitation or spontaneous vomiting, and choking when lying down. Repeated, forceful vomiting can also lead to Mallory-Weiss tears, or splits in the lower esophagus that can cause bleeding.

 

When laxatives are used to purge, it is not uncommon to experience diarrhea and rebound constipation, fluid retention, electrolyte abnormalities, and dehydration. 

 

Those with binge eating disorder may experience lower esophageal pressure that results in intense heartburn. Eating large amounts of food at one time can also result in bowel urgency, bloating, and nausea.

Managing GI discomfort in recovery

There’s good news: Most of the uncomfortable GI symptoms associated with eating disorders will resolve over time with nutritional rehabilitation. Your dietitian will work closely with you to devise a personalized meal plan to help you consistently and adequately nourish your body and restore your weight. This will in turn support the rehabilitation of your digestive system.

 

However, following a meal plan that requires you to eat more food can be extremely challenging, especially if it feels like it’s exacerbating some of your existing GI symptoms. Eating more when digestion is already slow can be very uncomfortable.

 

For this reason, your providers like your dietitian, your physician, and even a GI specialist may work together to help you find relief as you work through recovery.

Gastroparesis/slow digestion

 

Almost everyone who experiences gastroparesis as a result of their eating disorder will find complete relief with consistent, adequate food intake and, if underweight, weight restoration. To alleviate discomfort associated with gastroparesis, you can try the following:

 

  • Eating small, frequent meals 5-6 times per day
  • Drinking fluids between meals and not with meals
  • Eating soft, blenderized, or liquid foods, before graduating to solids
  • Eating slowly and chewing food thoroughly; ask your dietitian about digestive enzymes that may promote digestion
  • Continuing to eat fat-containing and protein-containing foods as tolerated; it is important to eat enough calories to support digestion
  • Sitting upright for at least an hour after eating
  • Incorporating gentle movement, like walking, if/when deemed appropriate by your recovery team
  • Taking prescription medication like metoclopramide to speed up digestion

 

Avoid doing the following:

  • Consuming carbonated beverages
  • Consuming high fiber foods or fiber supplements; fiber increases fullness and can slow stomach emptying even further
  • Cutting out entire food groups without consulting your dietitian

Constipation

 

Constipation is another digestive symptom that tends to resolve completely when the body receives adequate calories and digestion speeds up once more. Be sure to drink plenty of water, somewhere between 2-4 L or 64-108 oz per day. Drinking warm beverages like herbal tea or broth can also stimulate a bowel movement.

 

Contrary to popular belief, fiber-rich foods tend to make constipation from slowed metabolism worse. Your dietitian may recommend trying a low fiber diet until digestion speeds up, at which point you can slowly reintroduce fiber once more.

 

Be very wary of taking laxatives for constipation in your recovery. Stimulant laxatives can damage the colon and cause rebound constipation, which can create a vicious cycle. Osmotic laxatives can be helpful as they draw water into the bowel and help soften stool for passing without exacerbating constipation in the future. 

 

Bloating/distention

 

Bloating is a common side effect of gastroparesis and constipation in eating disorder recovery. When digestion slows, food has a longer time to ferment in the gut, releasing the gas that causes bloating. That said, resolving the aforementioned will also likely resolve uncomfortable bloating. 

 

Some foods/behaviors may make gas, bloating, and distention worse and are best to avoid: 

 

  • Foods high in fiber like beans, whole grains, fruits, and vegetables, especially when eaten in large amounts 
  • Artificial sweeteners and sugar alcohols which are often found in low sugar, low calorie, or diet foods
  • Chewing gum, which can result in swallowing a lot of air that then causes bloating
  • Drinking a lot of caffeinated beverages, like coffee or energy drinks, to suppress appetite, which can have a stimulant effect on the gut and cause urgent diarrhea
  • Drinking carbonated beverages, like diet soda or sparkling water, which introduces a lot of extra air that can cause bloating

 

Supplements like digestive enzymes and probiotics may be useful later in your recovery journey, but will not resolve slow digestion caused by restricted eating. Discuss what supplementation may be right for you with your dietitian.

Heartburn

 

When heartburn is caused by purging or by overeating, it will often resolve as a result of decreasing those behaviors. Some people find relief by avoiding highly acidic foods like tomatoes and citrus fruits, as well as spicy foods– although restricting any foods during recovery should be discussed with your dietitian first. 

 

Sometimes, heartburn can persist long into recovery, at which point your physician may recommend over-the-counter antacids or prescription proton pump inhibitors or a histamine 2 blockers, both of which decrease the production of stomach acid. If the lower esophageal sphincter has been permanently damaged and continues to let stomach acid wash back into the esophagus, you may be a candidate for surgical intervention.

 

Eating disorders, food sensitivities, and elimination diets

Many people in eating disorder recovery mistakenly assume their digestive problems are caused by food sensitivities or food intolerances because they experience so much discomfort when they eat. This can feel like motivation to further avoid certain foods. The truth is, your digestive system may be sensitive to certain foods early in recovery– not because of the food itself, but because gut motility and gut flora have been compromised.

 

The solution is to heal the gut by slowly reintroducing problem foods as a part of an adequate and balanced diet, not avoid them forever. 

 

In some cases, food sensitivities or food intolerances and your eating disorder may overlap, in which case it is important to assemble a team of practitioners who are knowledgeable about both eating disorders and digestive disorders. We generally do not recommend embarking on an elimination diet while in eating disorder recovery, because it encourages further restricted eating and can exacerbate anxious or obsessive thoughts about food.

Stress and self care during recovery

On top of everything else, eating disorders and digestion tend to go hand-in-hand with stress. The gut-brain connection is very strong! This means that stress can cause digestive discomfort, and digestive discomfort can cause stress. It’s a vicious cycle.

 

In addition to the above nutritional strategies, a little self care can go a long way to making yourself feel better when your stomach is in discomfort. You can try:

 

  • Wearing loose fitting clothes, especially pants that don’t put pressure on your tummy
  • Drinking warm, soothing beverages
  • Placing a heating pad or hot water bottle on your stomach
  • Going for a slow, relaxing walk
  • Doing gentle movement like yoga

 

Take note of where you are holding onto stress in your body even as you read this blog right now. In your jaw? Neck? Shoulders? Stomach? Glutes? Try taking regular breaks during the day to relax the muscles that support and surround your digestive system, from head to tail, especially before and after eating your meals.

 

Working with a therapist can also help you identify sources and remedies for stress in your life, which can support your overall recovery efforts.

Find support

Recovering from an eating disorder with digestive discomfort is hard, but you don’t have to do it alone. Find compassionate support with our expert eating disorder dietitians and gut health specialists. Book a consultation today!

 

 

 

  1. Janssen P. (2010). Can eating disorders cause functional gastrointestinal disorders?. Neurogastroenterology and motility, 22(12), 1267–1269. https://doi.org/10.1111/j.1365-2982.2010.01621.x

Kristin Jenkins is a dietitian nutritionist based in Maryland. She has been involved in the field of eating disorders and disordered eating for over 6 years and brings both personal and professional experience to her work serving clients who struggle with their relationship with food and their bodies.