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The Science of How to Poo!

Regular bowel motions and avoiding constipation is essential for gut health and preventing pelvic floor symptoms such as urinary incontinence and prolapse. But sometimes eating healthier, drinking more and increasing your fibre is not enough. So what actually is the best way to have a poo?

Before becoming a pelvic health physio I hadn’t really given it much thought - Everyone sits on the toilet and just goes …right?!?! But it turns out there is a lot of different ways people go to the toilet, some habits are good, some not so good ….and some a little shocking! But either way we should be going for a poo regularly and we want to be sure we are not causing any unnecessary trauma or pressure down there.

So what does the science tell us? Well - to understand the science we need to know a little about the anatomy of our bowel first

Bowel Anatomy and Physiology

Puborectalis pelvic floor muscle from Squatty Potty
Bowel Anatomy - Squatty Potty Image

When we are walking around, getting on with life - and not needing a poo our bowel – (or large intestine specifically) has a “kink” in it. This kink is caused by a muscle – puborectalis which is part of the pelvic floor muscle group. It wraps round a section of the bowel and puts a “U-bend” in the pipe. It helps to keep us continent and keep the bowel back behind the "U bend" and prevent the poo moving straight down to the rectum to tell us it wants to come out! Once the stool or poo has built up it will travel down to the dentate line in the rectum where some nerves sit ready to tell us we need to go to toilet.

Once we get to the toilet we sit down – we then require the puborectalis pelvic floor muscle to relax - This straightens the "U bend" in the bowel and allows the poo to pass. NO pushing or bearing down required!

However - in order to achieve optimal straightening and relaxation of puborectalis we need to be in a good position to allow it that movement. The ideal position is a squatting position rather than the upright position we tend to sit in on the westernised toilets we find in our homes now a days - So yes for those that have already made the link - this mean most of us are pooing with a kink in our bowel - and maybe why problems such as haemorrhoids, constipation and anal fissures are so common!

Squatty Potty - The Science behind the Perfect Poo Position

Ideally to optimise the straightening of your bowel for an effortless poo you need to

Comparing the upright sitting and squat position on the toilet
Squatty Potty Image : Anorectal Angle

  • Sit with your feet on a stool

  • Have your knees above your hips

  • Lean forwards.

This should limit the amount you have to strain and push to get a poo out, and reduce the risk of pain, haemorrhoids, piles, pelvic floor weakness, prolapse and bladder and bowel incontinence!

It’s also something I tell all my postnatal ladies about- because whether your are a c-section mum who’s tummy will not be able to effectively coordinate defecation in those early days and the abdominal scar can be really sore – or a vaginal delivery and dreading those first few poos – straighten up that U-bend to decrease some of that pressure.

So who new it? Were you pooing in the optimal position all along or will you be making some changes to protect you’re pelvic floor and bowel health? If you haven't got a stool in the bathroom then that's your job for today - no bathroom should be without one! It's worth mentioning here this tip is worth while remembering with children. If your child is constipated make sure they are in this nice position – it might be worth getting out a potty or a tall step to help them achieve the squat position to open up and straighten the anorectal angle and relax their pelvic floor.


The Images on this blog have been used from the Squatty Potty Website – They have designed a stool specifically designed to fit neatly round the toilet and raise your feet to recreate the optimal squatting position for bowel movements. They also have a video advertisement of a pooing unicorn (click the picture) which explains this science in a really funny and easy way to understand. Maybe not for everything but the kids will certainly love it!!!!!

This post is in no way sponsored to endorsing this product but the images I have used and referenced to demonstrate the theory. Any stool will do !


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