Period Poo: From Bloating to Diarrhoea, What Is up with Your Gut at That Time of the Month

Photo credit: Esther Sweeney - Getty Images
Photo credit: Esther Sweeney - Getty Images

From Women's Health

Period poo is the devil. In fact, that whole situation, around your time of the month, can be a painful, gassy affair: from bloating so bad that you physically can't get normal clothes on, through to constipation and then everything letting a little too loose.

Anecdotally, you know it to be true – and the data backs it up. One study showed that, in women with IBS (20% of the UK population will deal with the problem at some point, and women are believed to make up two thirds of all UK cases) symptoms of the illness were exacerbated in the days before their period, and that healthy women report looser stools at this time too.

Photo credit: Caiaimage/Paul Bradbury - Getty Images
Photo credit: Caiaimage/Paul Bradbury - Getty Images

So, what's going on here, biologically? And, when it comes to period poo and its band of merry friends, is there anything that we can do to lessen the impact?

Stay tuned.

Period poo: what the hell is up with your bowel and can it be fixed?


Why do I poo more on my period?

Right: the basics. On the run up to your period, your uterus lining thickens, because, if you were to conceive, this would be necessary to home and develop a foetus.

Because it's effectively getting bigger, it can press up against its neighbour the colon – hence bloating, constipation and general weird feelings in that area.

Why do I have diarrhoea on my period?

So, why is it that your period – or those joyful few days before hand, in which everyone that isn't you is a badly intentioned monster and a threat to the human species who must be destroyed with immediate effect – can trigger what we will henceforth call 'period diarrhoea?'

'It’s due to the body's change in hormones,' explains Dr Megan Rossi, Registered Dietitian, founder of The Gut Health Clinic on Harley Street and Research Fellow at King's College London (@theguthealthdoctor).

'On your period, you experience a fall in progesterone and an increase in prostaglandins [a group of lipids that constrict blood vessels in your uterus and make its muscle layer contract, so that you shed your lining].'

'This can impact your gut movements – such as the speed at which your body processes food – as well as the rate at which your gut absorbs liquid. This can trigger diarrhoea.'

Why is pooing on my period painful - and what's up with that terrible wind?

Your hormones going haywire can also result in period diarrhoea as a result of the gut/ brain connection that we've all been hearing so much about over the past few years.

'These hormonal changes also impact your emotions, which are created in the brain. They can feed down to your gut via the vagus nerve, again affecting gut movement and sensitivity,' elaborates Dr Rossi. Such changes in movement and heightened sensitivity can directly result in looser poo that lets you know it wants to vacate your body, like now.

It's hormonal changes that can also cause you to release extra terrible gas. As the gut bacteria is affected, so your wind is affected: mostly for the stinkier.

Can I change my lifestyle to make period poo less painful?

Sadly, the tricks to make the whole thing a little less... unpleasant are limited.

Photo credit: Tom Werner - Getty Images
Photo credit: Tom Werner - Getty Images

'It’s generally just one of those things,' says Rossi. 'But if what you're dealing with is severe, there are several diet strategies that can help.'

  • Limit how much caffeine and alcohol you're drinking (i.e. one flat white a day; no more than a few drinks a week)

  • Avoid super spicy food

  • Step away from very fatty meals (for example, cheese-heavy dishes)

  • Focus on eating smaller meals, rather than, for example, snacking all day and having a massive dinner

Try the above and see how you fare. Real talk, though: it's tragic but true that this is one of those cases of biology doing over female kind and making life harder than it needs to be.

Solidarity, sisters.