Autism and Constipation: Understanding the Gut Connection

“Autism and Constipation: Understanding the Gut Connection” was written by Rebekah Greenslaugh and edited/reviewed by Gabi Abreu, BSc, Maurya Hart, BSc, RD  and Jackie Silver MHSc, RD. 

Medical Disclaimer: The information in this article is meant for educational purposes only. It is not intended to be personalized medical or nutrition advice. For a plan tailored to your needs, please consult with a Registered Dietitian or qualified healthcare professional.

Disclosure: This post may contain affiliate links with which I may earn a small commission but at no additional cost to you. Affiliate links help bloggers like me to provide you with free content. All opinions expressed here are genuine. 

Last updated: April 7, 2025

Understanding the Link Between Autism and Constipation

Constipation is a common concern among many autistic people, which can cause pain, discomfort, and frustration. Understanding the connection between autism and constipation helps us to know what changes to make to improve the constipation, and how to address any challenges you may face along the way. In this blog post, we’ll walk you through how to tell if you are constipated, some common reasons autistic folks may experience constipation, and some simple changes you can make to your diet to reduce the risk of constipation. 

Autism and Constipation: What Does it Look Like? 

Constipation looks different in everyone, and sometimes we might not even notice the symptoms. Here are a few ways to tell if you are constipated:

• You are having bowel movements 3 or less times per week. Over one week, keep track of how many times you have a bowel movement. If it is less than 4 times in a week, this is a sign that you may be constipated.
• Your stools are lumpy, small or hard. If you notice that your bowel movements look like several small hard lumps, this could mean that you are experiencing constipation.
• You find that going to the toilet is uncomfortable or painful. Experiencing straining, discomfort, or pain while having bowel movements can be very unpleasant. These things can happen to people that are constipated.

Autistic children who are constipated may feel more frustrated or upset than usual, especially if they are physically uncomfortable (ie. bloated, gassy, have stomach pain). You may also notice your autistic child sitting or moving in different ways to try to feel more comfortable, which could indicate discomfort due to constipation. 

If this sounds like something you or your child might be experiencing, download our free Autism Constipation Guide to learn more.

What Causes Constipation in Autistic People?

Research indicates that gastrointestinal issues, including constipation, may be more common in autistic people. One recent systematic review and meta-analysis revealed that autistic children are at an almost 4 times higher odds of having constipation. However the reasons for this are not fully understood. It is likely a combination of dietary preferences, behavioral factors, differences in the gut microbiome, and side effects from medication.

Dietary Preferences: Autistic people may have specific foods they like to eat, because sensory sensitivities may make it difficult for them to eat vegetables, fruits, and whole grain foods that are high in fibre. Having a diet low in fibre, or not eating enough food overall, can contribute to constipation.

Behavioral Factors: Some autistic individuals, especially children, may have trouble knowing when they need to go to the bathroom. Because of this, they might not always go to the bathroom when they need to. Or, people could feel uncomfortable going to the bathroom if they are in a new place or not following their usual routine.

Gut Microbiome Differences: Recent research has begun to explore the role of the gut microbiome in understanding the link between constipation and autism. Autistic people have different bacteria in their gut microbiome, which may contribute to constipation.

Medication Side Effects: Certain medications that are prescribed to some autistic people may have constipation as a side effect. These medications may include Risperidone (Risperdal), Aripiprazole (Abilify), and selective serotonin re-uptake inhibitors (SSRIs, like sertraline or fluoxetine). There are several strategies a registered dietitian can use to help manage constipation as a side effect. 

At Jackie Silver Nutrition, our one-on-one virtual nutrition counseling can help autistic folks manage concerns such as constipation, using strategies that fit their specific situation and needs. Book a free discovery call to learn more!

Autism and Constipation: How to Manage Constipation Through Diet

Making certain dietary changes can help improve constipation symptoms in autistic individuals. One of the most effective is by increasing fiber intake. There are two main types of fiber: soluble and insoluble. 

• Soluble fiber dissolves in water to form a gel-like substance, which helps soften stools and makes them easier to pass. Foods rich in soluble fiber include oats, beans, lentils, apples, pears, bananas, and sweet potatoes.
  
• Insoluble fiber adds bulk to the stool and promotes the movement of food through the digestive system. Common sources of insoluble fiber include whole grains like whole wheat bread and brown rice, as well as vegetables such as carrots, broccoli, cauliflower, and leafy greens. 

In addition to consuming high-fiber foods, it may be useful to implement prebiotics or probiotics foods to alleviate constipation. Prebiotic and probiotics work by helping support a healthy gut microbiome.

• Prebiotics are a type of non-digestible fibers that are basically food for beneficial bacteria in your digestive system, helping them grow and thrive. Foods high in prebiotics include garlic, onions, asparagus, bananas, artichokes, and whole grains. Research indicates that supplementation with prebiotic dietary water-soluble fiber can improve gut dysbiosis and constipation symptoms in autistic children.
  
• Probiotics are live bacteria that directly contribute to a healthy gut microbiome. Incorporating probiotic-rich foods such as Activia yogurt (which has added probiotics to it), kefir, and fermented vegetables like sauerkraut and kimchi can help maintain balanced gut bacteria, which may improve bowel regularity and overall digestive health. 

While both prebiotics and probiotics are valuable, they serve different functions. Prebiotics provide nourishment for existing gut bacteria, while probiotics introduce beneficial bacteria into the gut. For those with aversions to foods containing prebiotics and probiotics, you may want to try a supplement or a daily vitamin containing prebiotics or probiotics. Make sure to consult a dietitian or physician when adding a supplement to your routine. 

Fibre and Fluid: It’s Important to Get Both!

Drinking enough fluids is equally important when increasing fiber intake. Water helps soften stools and makes them easier to pass. Without enough fluids, increasing fiber can actually worsen constipation. Here are a few ways to make sure you are drinking enough water throughout the day:

• Have a glass of water with each meal: Linking these two behaviours together (drinking and eating) will make it less likely that you will forget to drink throughout the day.
  
• Make water more interesting: If you find yourself getting bored with drinking water, try carbonated water options, or add sliced fruit or vegetables to your drink. Lemon, lime, orange, cucumber, and berries all add a delicious but subtle flavour to water! You can also add a water enhancer flavoring to improve taste.
• Try hydrating fruits: Hydrating fruits include watermelon, oranges, and berries, which can help increase your water intake when it may be hard to drink all of the fluids you need. 

Download our free Autism Constipation Guide to learn more about the role of fluid intake in managing constipation, and how to know if you are drinking enough.

In addition to increasing fiber, fluids, and potentially adding prebiotics or probiotics to your diet, establishing regular eating schedules can further promote predictable bowel movements, as the body’s natural movements are often stimulated after meals.

Remember that it is important to keep your individual preferences and sensory sensitivities in mind. Do not force yourself to consume anything that may feel too overwhelming or that you have aversions to, as that will not allow for sustainable changes that will help to relieve constipation long-term. 

How to Increase Fiber Intake for Autistic Individuals with Food Aversions

It can be challenging to make changes to your diet, especially if you have food aversions or sensory sensitivities. Try these tips for slowly increasing fiber in your diet to help manage constipation:

Start with one food: Introducing one new high fiber food at a time can help you avoid feeling overwhelmed. Add the new food into your diet for a week to see if you like it and if you notice any change to your bowel movements.

Blend fiber into smoothies and soups: Smoothies and soups are great for gradually increasing fiber intake. Start with a small amount of oats, chia seeds, or ground flax seeds blended into your usual recipe. Increase the amount over time to optimize your fiber intake. Aim for 1-2 tbsp of ground flax or chia seeds to your smoothies.

Make small changes: If you are used to eating fruit or vegetables without the skin, try keeping the skin on for extra fiber. Start with a few bites to see if you like it, and if you do, try eating the whole fruit or vegetable with the skin on. Other ideas can be to add a spoonful of flax seeds or chia seeds to your oatmeal, yogurt, or applesauce. If you love mac and cheese, try adding frozen peas to it for an added fiber boost! 

Incorporate higher fiber versions of safe foods: If you’re a pasta lover, try whole wheat pasta or lentil or chickpea pasta as these are higher in fiber. You can also try mixing half white flour with half of a higher fiber pasta. If you’re a fan of bread or crackers, you can try out whole grain versions. You can incorporate higher-fiber cereal with your favorite cereal. 

If switching to whole grains feels overwhelming, look for fiber-fortified pastas, breads, cereals, or snack foods that taste similar to your preferred versions but offer more fiber.

If you enjoy mashed potatoes, try mixing in some mashed white beans or using half sweet potatoes for extra fiber. For rice lovers, experiment with a blend of white and brown rice to ease into higher-fiber options.

If you like crunchy textures, you can try out crunchy air fryer chickpeas or store bought versions such as Three Farmers or Bada Bean Bada Boom.

Make Small Swaps Over Time: Instead of an all-or-nothing approach, gradually introduce higher-fiber foods alongside familiar favorites, allowing your taste buds and texture preferences to adjust at your own pace.

Try a supplement: Another option that may work for autistic people is to add a fibre supplement to your diet, such as Metamucil. Talk to a medical professional, such as a registered dietitian, to find a supplement that works for you.

Remember that if something feels too overwhelming to try, do not force yourself to try it. Instead, start exploring other options that may not feel as overwhelming to incorporate into your diet. Another great option is to work with a nutrition professional. Our one-on-one nutrition counseling can help you create a plan that actually works for you! 

Autism and Constipation: Conclusion

Dealing with constipation can be challenging and may require trying several different approaches to resolve it. It may include changing certain things that you eat and may alter your daily routine. By trying different strategies to see what works best for you, including seeking help from a professional, it is possible to improve constipation and the often frustrating challenges that come with it. 

👉 Check out these other recipes & blog posts about autism, constipation, and fiber:

• Autism Constipation Guide – Free PDF Download!
• Working with an Autism Dietitian
• Autism Safe Foods: Foods for Sensory Sensitivity
• How to Choose Cereals with Fiber
• Hemp vs Chia Seeds
• High Fibre One-Bowl Chocolate Chip Oatmeal Banana Bread

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