Period Poos: Let’s Talk About it…-image

Period Poos: Let’s Talk About it…

Medically Reviewed by Hertility on March 28, 2024

Period poo. What is it and why does it happen? In this article, we take a look at why our bowel movements seem to wreak havoc during our periods and some tips for managing any symptoms.

Quick facts:

  • Period poo can be any changes to bowel movements experienced during your period. 
  • Both diarrhoea and constipation are really common during menstruation. 
  • This can be caused by things like muscle contractions, hormone and diet changes and increased anxiety levels. 
  • If your period poos are bothering you, try our tips listed below.

What is period poo?

Period poo is basically any changes to your bowel movements during your period. This can be loose stools, diarrhoea, more frequent bowel movements, constipation, or more wind. 

Although period poo might not be the most hotly debated dinner party conversation, it’s actually really common—with one study citing that up to 73% of people who menstruate experience period poo

What causes period poo?

Throughout our menstrual cycles, our hormones cause a whole host of changes, some of which can affect our digestion and gastrointestinal tract. Here are some of the changes that occur in the lead-up to our periods specifically, which can lead to changes in bowel movements. 

Prostaglandins and muscle contractions

Prostaglandins are chemical messengers that your uterus (womb) produces around your period. They act on the uterine smooth muscles to help them contract and shed their lining each month. This means you have prostaglandins to thank for your period cramps. 

Sometimes, excess prostaglandins can act on smooth muscles elsewhere in the body, including the bowels. This causes an increase in muscle contractions in the intestines and bowel, leading to loose stools or diarrhoea. 

On the flip side, too little prostaglandins can have the opposite effect, causing things to slow down in the gastrointestinal tract. This is one theory of why some people experience constipation at the time of their period (3). 

Increased progesterone levels

Although the exact relationship is not well understood, your gut – as well as your uterus – also has receptors for sex hormones like progesterone and oestrogen. This means your gut is sensitive to the changes in hormones that come about at the time of your period.

Just before your period, progesterone levels are high, which can cause gut sensitivity, including bloating, diarrhoea or constipation, in some people. 

For people who already suffer from Irritable Bowel Syndrome, this can be exacerbated at this time of the month. If you’re experiencing flare-ups, stick to your prescribed symptom management plan and if you think you need more relief, speak to your doctor about alternative ways to manage your IBS during your period. 

Diet changes and cravings

An increase in progesterone levels just before our periods can cause cravings for certain foods. Changing your diet, for example eating more, consuming more carbs and processed foods, consuming less fibre and not drinking enough water can all affect digestion and lead to changes in stools. 

Increased stress or anxiety

A common symptom of Premenstrual Syndrome (PMS) that is often experienced just before or during our periods is increased levels of anxiety, overwhelm or stress. Each of these symptoms can lead to a change in bowel movements, as our guts are intimately linked to our stress levels (think the nervous poos). 

How to manage period poo symptoms

There are certain lifestyle changes you can adopt to help alleviate any gastrointestinal symptoms you notice around your menstrual cycle. Try some of the following tips to help make that time of the month a little less crappy.

Eat lots of natural fibre 

Fibre is like your bowel’s best friend—it helps to move things through and keep your digestion and bowel movements regular. Make sure you’re getting lots of high-fibre foods like fruit, vegetables and whole grains in the run-up to and during your period. Try not to overeat processed foods and carbs as these often have the opposite effect. 

Limit caffeine

If you’re experiencing loose stools and diarrhoea, try cutting down on your caffeinated drinks and foods (like dark chocolate). This is because caffeine stimulates the gut, resulting in you needing to go more frequently. 

Coffee in particular (even decaf) can stimulate the gut, so best to skip the morning coffee at your time of the month and opt for another way to energise yourself, like a morning walk or some yoga. If you do experience diarrhoea, be sure to increase your water intake to prevent dehydration. 

Get moving 

Movement and exercise are great for the gut and bowels. They help keep things moving through your digestive tract and can reduce the instances of bloating as well as helping to alleviate period cramps. If you’re not feeling up for your usual fitness routine, some yoga or simple stretching and walking are all great options.  

Stay hydrated

If you’re experiencing either constipation or diarrhoea, then drinking plenty of water is essential. Being adequately hydrated is very important for a healthy functioning gut and if you have diarrhoea you are at risk of becoming dehydrated quickly if you aren’t replacing lost fluids. 

Painkillers and stool softeners

It’s not unusual to mistake period cramps for bowel urges and vice versa during your period. Pain and cramps associated with either gut problems or your period can be eased with exercise, heat pads, or painkillers. You can also try stool softeners if you’re experiencing bad constipation.


Bríd Ní Dhonnabháin

Bríd Ní Dhonnabháin

Bríd is a Senior Scientific Researcher at Hertility, with a BSc (Hons) in Physiology from UCC and a Masters in Reproductive Science and Women’s Health from University College London. Her research interests focus on fertility preservation, tissue cryopreservation, foetal and maternal medicine and sexual health education

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