The Connection Between IBS and Eating Disorders
There is an undeniable connection between irritable bowel syndrome (IBS) and eating disorders. But which came first?
Did the eating disorder contribute to IBS symptoms, meaning recovery may help alleviate digestive distress? Or did the discomfort and symptoms of living with IBS contribute to the development of restrictive or disordered eating patterns?
In many cases, the relationship is not so straightforward. IBS symptoms can influence how someone eats, while eating disorder behaviours can also contribute to significant digestive distress. The two can become intertwined, making it especially important to look at the whole picture when supporting someone experiencing both.
What is IBS?
Irritable Bowel Syndrome, or IBS, is a chronic gastrointestinal condition that causes a significant amount of pain and discomfort in the individual. It is associated with abdominal pain, cramping and bloating, diarrhea and constipation. With IBS (Irritable Bowel Syndrome), different from IBD (Irritable Bowel Disease), these symptoms are present without any visual signs of damage or disease in your digestive tract.
IBS symptoms include:
Abdominal pain
Cramping
Bloating
Distention
Fullness
Burning sensation
Diarrhea and/ or constipation
Emotional stress and a negataive affect on quality of life
Increased urgency and/or frequency of bowel movements
While there is no one test to diagnose IBS, if you suspect you have IBS and are experiencing IBS symptoms, your doctor will review your symptoms, medical history and family history, perform a physical examination, and perhaps order additional testing (such as a colonoscopy, blood tests, etc.) to rule out any other health concerns.
How Can IBS Contribute to Disordered Eating?
Disordered eating patterns are commonly seen in individuals diagnosed with IBS, and there is certainly a relationship between IBS and eating disorders. Individuals struggling with IBS symptoms will often begin removing foods from their diet in an attempt to alleviate discomfort.
Over time, this can create fear around food and eating. Meals may become associated with pain, bloating, discomfort, or unpredictable bowel movements, which can lead to increased food avoidance, anxiety around eating, and restrictive eating patterns.
Food manipulation is common among individuals diagnosed with IBS, as symptoms can often feel closely tied to food intake and dietary changes. Many people begin adjusting, restricting, or avoiding certain foods in an attempt to reduce symptoms and gain a sense of control over their discomfort.
There is often strong feedback between food and symptoms for the person struggling with IBS, though that feedback may be physical, psychological, or both, depending on the individual’s level of stress, fear, and discomfort around the food in question.
In addition to self-directed dietary changes, many healthcare practitioners involved in IBS treatment, including nutritionists, naturopathic doctors, gastroenterologists, and functional medicine practitioners, may also recommend dietary modifications, along with lifestyle changes, medications, probiotics, and mental health support. This is in part because there is a very strong connection between the gut and the brain, which I will speak more about below.
It is not difficult to see how someone struggling with IBS could develop fear around food, dietary rigidity, food rules, and increased discomfort with eating socially.
What is the gut-brain connection?
Have you ever heard of the enteric nervous system?
It is one of the three main divisions of the autonomic nervous system and consists of neurons that govern the function of the gastrointestinal tract. It is capable of acting independently of the sympathetic and parasympathetic nervous system, and as such is nicknamed our “second brain”. Yes, your gut is truly your second brain!
We have all experienced this connection without realizing it:
Having “butterflies” in your stomach when nervous, excited or anticipatory.
Feeling nauseous or having an upset stomach when anxious, scared or angry.
Feeling like you can’t eat or digest your food when you are in the middle of doing something that is bringing up big emotions of any kind.
Needless to say, the gastrointestinal tract is sensitive to emotions and these emotions of all kinds can trigger different symptoms in our gut.
Our brain can influence our gut, AND our gut can influence our brain.
This is highly relevant when discussing IBS and eating disorders because the relationship works in both directions. Yes, the physical symptoms of IBS can absolutely make someone anxious or fearful around food, potentially leading to food avoidance, restriction, and distress around meals.
But the reverse can also be true.
Someone who feels significant anxiety, fear, or emotional distress around eating, such as an individual struggling with an eating disorder, may also experience increased stomach upset and IBS symptoms as a result of those emotions and the body’s stress response around food and mealtimes.
How Do Eating Disorders Affect Digestion?
I have been working with individuals with eating disorders as a nutritionist for over 12 years. In that amount of time, I have never met someone with an eating disorder who did not also suffer from digestive discomfort to some degree. Most people I have worked with and supported nutritionally through their eating disorder recovery, have experienced many, if not all, of the symptoms associated with IBS.
There are many reasons for this.
Digestive Issues and Anorexia:
When someone is restricting their food intake, their metabolism slows down significantly. With far less food being consumed than the body needs to function optimally, the body begins rationing the limited energy it receives in order to sustain essential functions required for survival, such as the heart and brain.
We do not need our digestive system to function optimally in order to stay alive - we simply need it to function well enough for the body to survive.
With Anorexia Nervosa, another way it can create digestive discomfort is that the limited amount of food intake (due to severe restriction) can cause delayed gastric emptying. This means that it takes a longer amount of time for the food to move from the stomach to the small intestine. This causes digestive discomforts such as bloating, pain, and nausea.
Digestive Issues and Bulimia:
People with Bulimia Nervosa struggle with binge eating and purging (such as self induced vomiting and laxative use). Self induced vomiting can cause acid reflux and stomach pain. Side effects of laxative use are stomach pain and cramping, bloating, nausea, and flatulence. Binge eating can cause stomach pain, bloating, nausea and diarrhea.
Bulimia can permanently damage your stomach and intestines causing other problems like constipation, diarrhea, and irritable bowel syndrome.
Digestive Issues and Binge Eating Disorder:
Those who engage in frequent binge eating episodes will experience many of the digestive discomforts associated with IBS. Binge eating leads to feeling very uncomfortably full and often feeling sick to your stomach. Common symptoms are bloating, abdominal pain, nausea, acid reflux, stomach cramping and diarrhea.
What is the best approach to support IBS and Eating Disorder Recovery?
When someone is experiencing both IBS symptoms and an eating disorder, one of the biggest concerns is that one condition may be treated without fully recognizing the other.
For example, someone may seek treatment for IBS without their practitioner recognizing the role that eating disorder behaviours may be playing in their digestive distress, or without realizing that an eating disorder is present at all. Without awareness of both conditions, recommendations such as food rules, dietary restrictions, or elimination diets may unintentionally reinforce or trigger the eating disorder.
At the same time, if eating disorder behaviours are contributing to digestive discomfort, IBS symptoms may not fully improve without addressing the eating disorder itself.
There is also a risk of going in the opposite direction and attributing physical digestive symptoms entirely to anxiety or the eating disorder, resulting in the individual's IBS symptoms not being taken seriously or appropriately investigated.
This is why supporting someone with both IBS and an eating disorder requires nuance and a holistic, multifaceted approach. Both conditions need to be taken seriously, and neither should be overlooked in the treatment of the other.
IBS symptoms should not automatically be attributed to an eating disorder, and eating disorder behaviours should not be overlooked when someone is experiencing digestive distress.
When both are present, the goal is not simply to remove foods or eliminate symptoms. It is to understand the bigger picture, support the digestive system, address the eating disorder, and create a path toward feeling safe and nourished around food again.
If you or your loved one is struggling with an eating disorder alongside IBS or ongoing digestive symptoms, you don't have to navigate the two separately. I offer individualized nutrition support for eating disorder recovery, including support for the complex relationship between food, digestion, and the eating disorder.
If you'd like to talk through what you're experiencing and learn what support could look like for you, you're welcome to book a complimentary discovery call.