Why Eating Disorders can feel like IBS

When Your Gut Is Struggling: Eating Disorders, Digestive Symptoms, and Why It’s Often Mistaken for IBS

Digestive issues are incredibly common in people experiencing eating disorders or chronic restriction. In fact, many people seek help for gut problems long before they realize their relationship with food may be contributing to their symptoms. Bloating, constipation, nausea, stomach pain, fullness after small amounts of food, reflux, and unpredictable bowel movements can feel alarming and very real — because they are real.

But one important thing often gets overlooked:

Sometimes the gut is not “broken.” Sometimes it’s underfed, stressed, or adapting to inconsistent nourishment. This is why eating disorder symptoms are frequently confused with conditions like Irritable Bowel Syndrome (IBS).

Our gut and brain are connected via the vagus nerve. This makes our digestive system highly sensitive to stress, anxiety, hunger, meal timing, changes in food intake, hormones, and nervous system activation. When the body is under stress- including the stress of restriction, inconsistent intake, yo-yo dieting, restrict-binge cycles, compensatory behaviors like purging - it will have significant impact on the gut.

Common Gut Symptoms in Eating Disorders

Constipation

When food intake decreases, the digestive system often slows down to conserve energy. Restrictive eating can also lead to missing key nutrients that promote gut motility. Constipation can be a result of the body having less food volume to move through, reduced muscle contractions in the gut, reduced gut microbiome, lack of fluid intake and lack of fiber- both soluble (i.e.. grains) and insoluble (ie. leafy greens)

Bloating

Bloating is one of the most common complaints during restriction and recovery. It can happen because digestion slows down when the body is underfed. Food can also end up staying in the stomach longer when the gut is not utilized regularly throughout the day. Constipation often also increases gas buildup. Many people interpret bloating as proof that something is “wrong” with them or that they are eating incorrectly, when sometimes it’s actually a sign the body is trying to adapt to the change in eating patterns.

Early Fullness

People recovering from restrictive eating often feel full very quickly. This can happen because prolonged under-eating may slow stomach emptying, a condition sometimes called delayed gastric emptying or gastroparesis-like symptoms. it can seem like the stomach adapts to smaller amounts of food over time (despite the body prefering adequate intake), so normal portions can temporarily feel overwhelming or uncomfortable.

Reflux, Nausea, Gut Pain

Irregular eating patterns, purging behaviors, stress, and slowed digestion can contribute to increase in acid reflux, nausea, and gut pain. Increase in acid reflux can be due to loosening of esophageal sphincter from frequent purging. Nausea can appear during prolonged starvation where stomach acid begins to irritate the gut in absence of food. This is often why people will report feeling nauseous in the morning after restricting intake for a period of time. Last but not least, our digestive organs are made of muscles that need to be “exercised” regularly in order for effcient function. So when it is not used to its full effects ie. skipping meals, avoiding food groups, it can become pretty wonky at digestion- resulting in a lot of pain and cramps when digesting food.

These symptoms can become especially distressing because they may reinforce fear around eating.

Diarrhea or Urgency

How fun! We discussed how eating disorders can cause constipation, however on the flip-side it can also induce diarrhea and frequent loose stools. Frequent binge eating, laxative use, anxiety, missing nutrients and inconsistent eating can also trigger diarrhea or urgent bowel movements.

The digestive system often becomes more reactive when eating patterns are chaotic or unpredictable.

Why Eating Disorder Symptoms Get Mistaken for IBS

IBS is a real gastrointestinal condition involving altered gut-brain interaction and digestive symptoms. But many symptoms of eating disorders overlap with IBS, including what has been listed above- constipation, bloating, diarrhea, stomach/bowel pain, early satiety.

Because of this overlap, people may receive an IBS label without anyone exploring their eating pattern and relationship with food. It is important to explore the following before attributing gut symptoms to IBS:

• Irregular eating such as skipping meals/snacks, yo-yo dieting

• Inadequate nourishment such as restricting food intake, restricting food groups, dieting and under-eating

• Binge eating

• Significant and recurring emotional eating

• Food fears or thinking about food all the time

• Compensatory behaviors like purging, over-exercising, and laxative use

• Guilt and shame around food and eating

The Risk of Misdiagnosis

When eating-disorder-related gut symptoms are mistaken solely for IBS, treatment can unintentionally worsen the problem. Treatment for IBS often relates to elimination of certain trigger foods, restriction of certain carbohydrate sources, and following a lot of food rules. This can greatly reinforce restriction eating patterns and further disrupts digestion for people with an eating disorder. It can impact someone who is already prone to under-eating to having an even harder time finding foods they can fuel with, and in the long-term worsen gut function rather than improving it.

Head to part-2 to learn more about how to support the gut in the context of an eating disorder.

Disclaimer: the information provided is not intended as medical advice or to diagnose or treat a medical disease. It is strictly for informational purposes. Consult with your medical provider such as a dietitian before implementing any dietary changes, the information provided does not replace medical advice provided by your healthcare provider.

Created with AI assistance by Abby Hsiao, Dietitian

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Work cited

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