# Period poos: yes, they are a thing

> Why your bowels get involved, and what helps.

Category: Period care · 3 min read · Written by the Splash team · Sources checked October 2026
URL: https://splash.care/learn/period-care/period-poo

## Quick answer

- Gut symptoms around periods are very common.
- Prostaglandins are thought to speed up your bowels.
- Painful poos on your period, bowel bleeding, or lasting changes are worth a GP visit.

If your bowels go a bit wild around your period, you have lots of company. In a study of 156 healthy women, about 73% had at least one gut symptom, like tummy pain, diarrhoea, constipation or nausea, just before or during their period.

**73%** of 156 women in a 2014 survey had at least one gut symptom before or during their period. Tummy pain and diarrhoea were the most common.

## Why it happens

The same [Prostaglandins](https://splash.care/learn/glossary/prostaglandins) that make your womb contract are thought to affect the gut nearby, speeding things up. [Hormone](https://splash.care/learn/cycle-basics/hormones-explained) shifts before your period may also cause constipation or [bloating](https://splash.care/learn/body-literacy/bloating) for some people. The exact mechanisms are still being studied.

## What can help

- Drink plenty of water, especially if you have diarrhoea.
- [Fibre](https://splash.care/learn/glossary/fibre) from fruit, veg and wholegrains can help keep things regular. Soluble fibre such as oats or linseed can help if you are constipated.
- Go easy on [caffeine](https://splash.care/learn/nutrition/caffeine-alcohol), alcohol and very spicy or fatty foods if they make it worse. The NHS lists these as common triggers for [IBS](https://splash.care/learn/glossary/ibs) flare-ups.
- Anti-inflammatory painkillers reduce prostaglandins and may ease [cramps](https://splash.care/learn/period-care/cramp-relief). Whether they also settle loose stools is less well studied, so treat this as something to try only if they are suitable for you.

> **Splash says:** log gut symptoms alongside your period. If they always cluster around it, that is useful to know and to tell a GP.

**Myth:** Loose stools on your period mean you ate something bad.

**Fact:** They can simply be your cycle. If they come in a pattern with your period, prostaglandins are a likely cause.

### When to see a doctor

See a GP if you have pain when pooing or peeing during your period, because the NHS lists this as a possible sign of endometriosis. Also go if you have bowel symptoms lasting over 4 weeks (which could be IBS), a change in bowel habit that lasts, or blood in your poo. Ask for an urgent appointment if you have lost a lot of weight for no reason, bleed from your bottom, have bloody diarrhoea, or find a hard lump in your tummy.

## Sources

1. [Bernstein et al. (2014) Gastrointestinal symptoms before and during menses in healthy women, BMC Women's Health](https://pmc.ncbi.nlm.nih.gov/articles/PMC3901893/)
2. [NHS: Period pain](https://www.nhs.uk/symptoms/period-pain/)
3. [NHS: Irritable bowel syndrome (IBS) symptoms](https://www.nhs.uk/conditions/irritable-bowel-syndrome-ibs/symptoms/)
4. [NHS: Endometriosis](https://www.nhs.uk/conditions/endometriosis/)

This is general information, not medical advice. Splash can’t diagnose. If you’re worried, talk to a GP, pharmacist or sexual health clinic. In an emergency call 999 (UK) or 911 (US).