Constipation and Diarrhea in Autism (AKA The “Poop” Page)


Common Signs of Constipation in Autism
Diarrhea in Autism
Possible Causes of Chronic Constipation and Chronic Diarrhea
Tips to Help with Constipation and Diarrhea
Products that Help Alleviate Constipation
Warning About MiraLAX
Complex Gastrointestinal Issues

Autism and gastrointestinal problems go hand-in-hand for many kids. This meta-analysis of several studies published in the Journal of Pediatrics estimates that “the odds of GI symptoms in children with ASD are four times more prevalent than for children without ASD.” The analysis indicated higher levels of GI symptoms in all four areas including general GI concerns, diarrhea, constipation, and abdominal pain.

If the bowels are not moving daily, it can be very painful for the child and toxic to overall health. In this article, we will discuss both constipation and diarrhea and tips to help your child with both.

When we think of constipation, we usually think of stool that looks like little, hard rocks that are really hard to push out. That kind of constipation usually resolves with more water, fruit, veggies, and fiber in the diet. This usually isn’t the kind of constipation we are talking about with Autism Spectrum Disorder (ASD) kids. It’s not a matter of texture; it’s a matter of frequency. Our kids’ stool is often mushy. It should be easy for them to pass, but they have to strain to get this mushy stool out. This is known as incomplete evacuation.

In fact, many parents of kids with autism do not even know their child is constipated because the child is still having daily bowel movements. The child is simply not excreting enough stool. At TACA conferences, doctors tell parents that you should see 8-10 inches of stool per day. If a child skips a day, then they have that much more stool to expel.

An abdominal x-ray (KUB) can help diagnose constipation if you suspect this may be a problem. It can also tell the doctor the location of the built-up stool or if there is excess gas.

Common Signs of Constipation in Autism

Troubled Sleep

A constipated child often wakes in the middle of the night because of discomfort and has a hard time getting back to sleep.

Aggression and Self-Injurious Behavior

Constipation is extremely painful, which, in turn, makes the child miserable and sometimes aggressive. If your child can’t tell you they are in pain, they use their behavior as communication. Often the child has suffered with this pain for a very long time and therefore, doesn’t know what it is like to not have extreme gastrointestinal pain.

The Appearance of the Stool

Look at the Bristol Stool chart. Types 1 & 2 are obvious indicators of constipation. However, types 6 & 7 may indicate diarrhea or a blockage (caused by constipation) as discussed above.

Bristol Stool Chart (constipation and diarrhea)


Toe-walking may occur because constipation is so painful or it may be a child’s way to withhold stool. This paper on constipation states “standing on toes, extending legs or rocking back and forth preventing anal relaxation are typical features” (of constipation).

Loose Bowel Movements

Interestingly, loose stool can be a red flag for constipation. Bowel movements that alternate between not enough stool and loose stool are also a problem. This is because the loose stool is able to squeeze around the blockage of stool in the colon.

Child is Not Growing

A lack of growth may be due to malabsorption problems or simply a lack of appetite due to constipation. This study shows that constipation has a direct effect on growth in children.

Stinky Poop

Contrary to popular opinion, poop should not smell horrible. If stool smells bad, it is probably either an overgrowth of pathogenic bacteria or the stool has been sitting and fermenting in the colon for far too long. Stool that moves through the intestines at the right pace should not smell awful.


This is seen when the child leans over something to put pressure on the abdomen. This counterpressure relieves pain.

Bloated Belly

Sometimes our kids have huge, distended bellies. This may be because there is a build-up of old stool or another problem such as small intestine bacterial overgrowth (SIBO).

Posturing and a distended, bloated stomach are examples of two possible signs of constipation that are often overlooked.

Streaks In Underpants and Poop Accidents

This can be a sign that the child is not fully eliminating all the stool in the colon. Also, if the child has an over-stretched rectum, the body loses the urge to poop and they may have accidents without even knowing it.

This short video explains why constipated kids will have poop accidents and smears in their underpants.


Too much stool in the rectum doesn’t leave room for the bladder to expand, so urine accidents become more common.

Unable to Toilet-Train

When stools are unpredictable or hard-to-pass, toilet-training is going to be almost impossible. Fixing the constipation needs to come first.

Toilet-Trained Kids are Taking Too Long to Poop

It should not take a long time to pass stool. If it does, that is a sign of a problem.

Stool Impaction

A stool impaction is a severe bowel condition in which a hard, dry mass of poop becomes stuck in the colon or rectum. It is very painful. Watch for clues such as a distended tummy, night waking because of pain, and sometimes dramatic changes in behavior. Sometimes children with stool impaction will produce thin, ribbony stool in the toilet or have diarrhea every day or every few days.

X-ray showing severe constipation/stool impaction.

Stool impaction can be diagnosed with an abdominal x-ray (KUB). If the impaction is large enough, it may require medical attention. A clean-out will likely be prescribed. See information on how to do a clean-out without MiraLAX, which has safety concerns, here.

Sometimes kids that have autism alternate between constipation and diarrhea. These children can be dealing with multiple bowel issues, and the pendulum swings back and forth in extreme ways. Finding a balance with diet, natural or prescribed remedies, and working with your doctor is key to meeting your child’s needs.

Diarrhea in Autism

Frequent diarrhea that occurs once to several times a day per day is a serious medical issue. If diarrhea continues for a prolonged period of time (3-4 days), please contact your doctor immediately.

Possible Causes of Diarrhea

  • Too much:
    • Fruit
    • Magnesium
    • Vitamin C
    • Essential fatty acid (Omega 3s)
    • Fiber
  • Drinking bath water containing Epsom salts
  • A reaction to food(s) or additive(s)
  • Parasites such as Giardia
  • Pathogenic bacterial overgrowth
  • Antibiotics (that have skewed the balance of the gut flora)
  • Infection such as Clostridium Difficile
  • Inflammation in the intestines
  • And other issues that need to be identified by a pediatric gastroenterologist.

Possible Causes of Chronic Constipation and/or Diarrhea

Supplements and Medications

Prescribed medications and supplements commonly given to people with autism can impact the bowels. 

  • Medications such as Risperidone, Abilify, and some prescriptions used to treat ADD/ADHD have side effects that include constipation.
  • Iron, calcium, and 5-HTP are supplements that commonly cause problems with constipation. You may need to add or increase magnesium citrate or something else to keep stool soft. Talk to your doctor.
  • Binders such as activated charcoal can also cause constipation. If using, give them with plenty of water and monitor your child.
  • Some probiotics, especially Saccharomyces boulardii, can cause constipation or diarrhea.
  • Too much magnesium, fish oil, or vitamin C can cause loose stools.
  • When starting or increasing these supplements/medications, watch the bowels carefully.

Mitochondrial Dysfunction

Sometimes constipation is due to mitochondrial dysfunction, which is very common in kids with autism. It can slow down gut motility causing chronic constipation. Therefore, addressing mitochondrial dysfunction with a mitochondrial cocktail can be very helpful. More about this topic here.

Food Allergies/Sensitivities

Food allergies (IgE) or sensitivities (IgG) could be at the root of the problem. Testing for food allergies (IgE) and food sensitivities (IgG) may be helpful. More information on testing in the Introduction to the Gluten-Free, Casein-Free, Soy-Free and Diet article.

Gut Dysbiosis

Test for and treat fungal overgrowth and pathogenic bacteria in the gut.

Often times, constipation and/or diarrhea can be caused by too much fungal overgrowth and/or an overgrowth of bad bacteria in the gut. Anti-fungal medication or an antibiotic may help relieve constipation. Discuss with your functional medicine doctor.

Thyroid Dysfunction

Thyroid dysfunction, which is often found in kids with ASD, can cause issues with bowel movements. Hypothyroidism can contribute to constipation and many other issues including developmental delay. Hyperthyroidism, while less common, can contribute to diarrhea.

A Need for Fiber

Fiber may help with constipation. But be careful - Your child must be drinking enough water with fiber supplementation or fiber may backfire on you. Check with your doctor about brands and dose. Favorite brands include Fibersure, ClearFiber, and TruFiber. Always check the ingredients on the label as they change on occasion and sometimes contain wheat or soy products.

Fiber may also be problematic if your child has mitochondrial dysfunction, SIBO, or if the child has pathogenetic bacterial overgrowth. Fiber will feed this overgrowth. In addition, a fiber supplement may cause fluffy stool.

Tips to Help with Constipation and Diarrhea

Below you will find tips to help alleviate constipation and/or diarrhea. Some of the suggestions listed work for constipation, some for diarrhea, and many work for both.  Tips that work for constipation are indicated by the letter “C” inside of a red circle.  Tips that work for diarrhea are indicated by the letter “D” inside of a red circle.


  • Eliminate gluten, dairy, soy, artificial ingredients, and limit sugar.
  • Recognize foods in your child’s diet that are constipating. Milk and cheese are very constipating and sometimes just eliminating all dairy from the diet can make a big difference.
  • Bananas and nuts can also be very constipating. Monitor their intake.
  • Lots of whole foods, fruits and vegetables are helpful.
  • If that doesn’t help, investigate other options like the Specific Carbohydrate Diet, Failsafe diet, or a rotation diet.

Healthy Fats

Healthy fats can help with constipation. Make sure your child is getting enough healthy fats in his/her diet. Some examples would be:

  • Fish oil, cod liver oil, coconut oil, avocado oil, almond oil, MCT oil, extra virgin olive oil, and more.

Too many fats cause loose stool so be vigilant. Talk to your doctor about which oils and how much of each would be good for your child.

Fermented Foods

Fermented foods have good live bacteria in them and can help with formed bowel movements. Start low (a teaspoon) and slowly work your way up. Be careful with fermented food if your child is sensitive to high histamine foods.

Drink Water

Hydration is key! Filtered water should be the beverage of choice. It is extremely important for keeping the gastrointestinal track moving well. Make sure your child is getting plenty of water every day, even if that means sending them everywhere with a bottle of water.


Exercise helps constipation in two ways. First, it decreases the time it takes food to move through the large intestine. Secondly, exercise stimulates the natural contraction of intestinal muscles.

A Bathroom Stool

Placing your feet on a bathroom stool while sitting on the toilet can help you poop according to this study published in the Journal of Clinical Gastroenterology. The Squatty Potty is a stool made for this purpose but any stool with work. This video explains why squatting is far better than sitting on a toilet.

Abdominal Massage

Abdominal massage can be effective in treating chronic constipation by increasing the number of bowel movements, decreasing transit time and relieving pain. Here is a video that explains exactly how to do a bowel massage.

Raw “Green Juice”

Naturally occurring enzymes in raw fruits and vegetables will help digestion.

  • Take fresh organic green fruits and veggies and puree them in the blender or juice them. Examples include spinach, pear, celery, or whatever is tolerated.
  • Give one tablespoon of the “green juice” with each meal.
  • If you use a mason jar to store the juice or smoothie in the refrigerator, it can last up to 3 days.

Fresh Squeezed Lemon in Warm Water

  • Lemon makes the body more alkaline.
  • It stimulates the liver and promotes bile flow which in turn aids in digestion.
  • Give this on an empty stomach, preferably first thing in the morning.
  • Make sure to use a straw when drinking lemon water to protect teeth.
  • This article has more information on the benefits of lemon water.

A Warning About Miralax

Oftentimes, parents are told to give their child MiraLAX to help alleviate constipation. MiraLAX is polyethylene glycol (PEG) 3350. Polyethylene is the most common form of plastic. When combined with glycol, it makes a liquid.

A photo of a bottle of Miralax, which is often given to alleviate constipation.

When a child takes MiraLAX, they are drinking plastic. If that child has a permeable GI lining, as many kids with autism do, then the plastic has the potential to cross directly into the bloodstream.

This study showed that PEG inhibited most of the metabolic activities of the fecal flora, and this was shown by decreases in total short-chain fatty acids, butyrate, acetate, and fecal bacteria mass. These short chain fatty acids keep the colon healthy and it is unknown what the outcome will be when PEG is used long-term.

Butyrate, in particular, is needed for energy metabolism and since we already know that kids with autism have trouble with producing enough energy, we don’t want to give them a product that will make it worse.

It is important to make educated decisions. More information on MiraLAX from the FDA here.


Prolonged diarrhea and/or constipation are NOT acceptable for any child and both require medical intervention. It is time to seek medical attention if these symptoms continue for more than three to four days.

Note: If a symptom carries fever, long periods of irregular bowel movements, which can lead to dehydration or other issues, extreme change in behavior, or loss of sleep or appetite for an extended period of time, please contact your doctor immediately.

*All content of this article was created for informational purposes only and is not intended to be a substitute for professional advice, diagnosis, or treatment. Always seek the advice of your physician, therapist, or other qualified health provider with any questions or concerns you may have.