Constipation and autism

While many autistic children have no difficulties with constipation, it can often be a problem. This can cause a delay in potty training and your child achieving reliable bowel and also bladder control.

Constipation can also cause pain and anxiety for these children and their parents on top of the other issues they are facing day to day.

Keep reading for more information and support to help your child.

Reasons why autistic children become constipated

  • Constipation affects 1 in 3 of all children anyway.
  • Autistic children often have restricted diets which makes constipation more likely.
  • After one large, painful poo children often withhold their poo to stop it happening again.
  • Children on the autism spectrum may learn that poo goes in the nappy, so they wait until this is put on as they find change difficult.
  • They may not remember to drink regularly or not like the taste of water.
  • Feeling anxious about being in the toilet or bathroom, especially away from home.

How can you spot constipation?

There is often a delay recognising/spotting when a child is constipated and few definite signs so it’s important to look at the child’s bowel pattern carefully.

The normal bowel pattern is to have a soft sausage shaped poo at least three times a week, and some people have a more frequent pattern, sometimes several times a day.

One alert sign is an alteration in bowel pattern, and this may happen at a time when routines change such as going on holiday, a new baby arriving or starting play group. When children are not well this may be associated with a change in bowel pattern linked to different fluid intake and food.

Large irregular painful bowel actions are usually associated with constipation. The abdomen may be distended at times. Children can sometimes have abdominal pain and become irritable with a poor eating and sleeping pattern.

A poo backlog

The longer the poo stays in the large bowel, the more water it will lose. If it stays inside for too long it will dry out and become hard and knobbly (see Bristol stool chart).  Sometimes this can break up and little bits drop out – like rabbit droppings!

Sometimes the large bowel becomes distended with a large amount of poo blocking the way out, and then soft poo from above leaks round the lump causing frequent runny poos, that children can’t control. They don’t feel the sensation that they need to go to the toilet as the bowel is stretched. This is known as overflow soiling

Overflow soiling

It’s really important that parents understand that this leakage/soiling/overflow is not diarrhoea. (Overflow and diarrhoea can often be confused.) Because the poo has been in the large bowel for a long time it is also more smelly and it is difficult to wash off, so lots of parents have to throw away their children’s pants.

Children with constipation often have wee problems too as the large bowel may occupy the space where the bladder wants to expand and fill, and sometimes it puts pressure on the bladder.


It is advisable for children with constipation to have a physical examination by a medical professional. Usually further investigations are not needed.

The NICE guidelines recommend this is done to make sure any underlying condition is detected.

How to relieve constipation

Management and treatment of constipation

For children on the autism spectrum there should always be a combined approach with medication and behavioural strategies as well as regular support and follow up.

Healthy eating including a diet containing fluid and fibre is helpful to maintain a regular bowel pattern, and help to prevent the development of constipation. This is not always easy for children with autism. I have had some success with vegetable slush puppies and cut out shapes with pastry cutters from vegetables. You have to be creative and flexible.

Disimpaction followed by maintenance

When constipation has developed it needs to be effectively treated, and the NICE guidelines state that to do this appropriate medication is needed.

This is a two stage process, disimpaction to empty the bowels, followed by regular maintenance treatment. This often needs to be continued for several months, and often sometimes longer.

The problem with constipation in children is that the bowels have often become stretched, so if treatment is stopped too soon the constipation recurs. The bowels do eventually recover their natural tone, but this does take some time.

There aren’t any risks in continuing the medication, and there are great deal more problems from continued constipation. Children’s anxiety and fear about opening their bowels will usually take a great deal longer to fade.

Stool softening laxatives

There are a range of treatment options including stool softeners like Lactulose and stimulant laxatives like Senna. But the recommended first option is a Macrogol such as Movicol. For children on the autism spectrum who often find that new flavours and tastes are not easy to accept, the best medication is always the one that is acceptable and that they will take regularly.

Withholding Poo

I highly recommend parents read a book by Dr Antony Cohn: Constipation, Withholding and Your Child. 

He explains how withholding develops, by children holding on to their poo, often triggered by an uncomfortable or scary bowel action. Even tiny babies can withhold. He points out that children’s bowels are working normally and the straining is children trying to hold their poo in, and not trying to push a hard poo out. Dr Cohn emphasises the cycle:

‘Poo is pain. I want to stop it. The more I stop it the more it hurts. The more it hurts the more I want to stop it’

The treatment needs to ensure that the bowel is fully emptied and also kept empty for some time until the time a new pattern is fixed and reliable.

Behavioural programmes

Toileting programmes need to include strategies to help with children’s understanding of using toilets and building their confidence. To do this, children may like

  • Stories
  • Pictures
  • Games
  • Blowing toys and bubbles
  • Competitions
  • Even a visit to the local sewage works!

Dealing with anxiety

Most children with autism who have difficulties in pooing in the toilet are troubled by anxiety, and are not being difficult. They often need a great deal of reassurance. Other things that may help are:

  • Breaking the task into small steps
  • Building their confidence in other skills
  • Keeping their environment calm
  • Distractions e.g. fiddle toys, music
  • Abdominal massage

Sensory problems

Sometimes reluctance to let go of the poo in the toilet is linked to children on the autism spectrum having difficulties linked to either increased or reduced reaction to sensory messages.

This may affect their balance on the toilet or their awareness of body sensations. Anxiety linked to sensitivity to smells, sounds or light may also affect a child’s ability to sit on the toilet and relax. Understanding the child’s individual pattern is important in finding the best solutions.

Future outlook

With treatment and behavioural approaches, constipation in children with autism can be treated and they can become continent. It is important to monitor their bowels as constipation can easily reoccur. It can help to keep a monitoring record using ERIC’s Poo Diary.

Other sources of help


Find out why some children smear their poo and how you can support them. Information on the links between children's toileting and sensory needs. 

Children with special needs may take a little longer to potty train, but we have lots of information and tips on to support you and your child with this process.

Find out why poo withholding happens and how to help your child overcome this stressful cycle of behaviour.

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