Why Do I Get Diarrhoea on My Period? The Science Behind Period Poops (And What Actually Helps)

Let's talk about something that deserves far more attention than it gets...

Period poops.

Yes, they're real.

And if you've ever found yourself making more trips to the bathroom than usual during your period and wondered, "What on earth is going on?"—you're definitely not alone.

For years, I honestly thought this was just one of my body's strange little quirks. I assumed I was unlucky or that something I'd eaten wasn't agreeing with me.

It turns out there was a perfectly scientific explanation all along.

Millions of women experience changes in their digestion during their menstrual cycle, yet it's still one of those symptoms that hardly anyone talks about. We're taught about cramps, bleeding, pads and tampons—but nobody really prepares us for the possibility that our digestive system might decide to join the monthly party too.

The good news?

In most cases, period diarrhoea is completely normal. It's caused by the same hormones that help your body shed the lining of your uterus each month.

Once you understand what's happening inside your body, those frustrating bathroom trips start to make a lot more sense.

First Things First... You're Not Weird

If you've ever experienced loose stools, sudden urgency, stomach cramps or multiple bathroom trips during your period, you're in very good company.

Many women notice digestive changes during menstruation, including:

• Loose stools
• Diarrhoea
• More frequent bowel movements
• Bloating
• Gas
• Stomach cramps
• Nausea
• Food sensitivities

Interestingly, not everyone experiences the same symptoms.

Some women become constipated in the days leading up to their period, only to develop diarrhoea once bleeding begins. Others experience bloating and gas without any noticeable changes in their bowel habits.

Every body responds a little differently to hormonal fluctuations, which is why your experience may not be exactly the same as your friend's—or even the same from one month to the next.

The important thing to remember is this:

Period poops are incredibly common, and in most cases they're simply another part of your body's natural menstrual cycle.

What Are "Period Poops"?

"Period poops" is the informal name many women use to describe the digestive changes that happen around the time of menstruation.

For some, this means going to the bathroom more often. For others, it means looser stools, stronger urges to poop, or feeling like they can never quite stray too far from a toilet during the first day or two of their period.

Some women even notice that their bowel movements become easier and more regular during menstruation after feeling constipated before their period.

These changes aren't caused by the food you've eaten, poor digestion or something being "wrong" with your body.

They're largely driven by your hormones.

Once you understand how those hormones work, the mystery behind period diarrhoea becomes much easier to understand.

Why Does Period Diarrhoea Happen?

The biggest reason comes down to tiny hormone-like substances called prostaglandins.

Although the name sounds complicated, prostaglandins have one very important job during your period: they help your uterus contract so it can shed its lining.

Those contractions are what allow your menstrual flow to leave your body each month.

But here's the catch...

Prostaglandins don't only affect your uterus.

Because your uterus and intestines sit very close together in your pelvis, prostaglandins can also stimulate the smooth muscles in your digestive tract.

When those bowel muscles contract more than usual, food moves through your intestines more quickly.

That means your body has less time to absorb water from your stool, resulting in softer stools or diarrhoea.

It's essentially a side effect of the very process that allows menstruation to happen.

How Hormones Affect Your Digestive System

Your menstrual cycle is controlled by a delicate balance of hormones, and these hormones influence far more than just your reproductive organs.

They can also affect your digestive system.

Here's what typically happens throughout your cycle.

Before Your Period

During the second half of your menstrual cycle, levels of progesterone rise.

Progesterone naturally slows down many muscles throughout the body—including those in your digestive tract.

As a result, many women notice:

• Constipation
• Slower digestion
• Bloating
• Feeling unusually full
• Gas

If you've ever wondered why you feel sluggish or "backed up" a few days before your period starts, progesterone is usually the reason.

Once Your Period Begins

When menstruation starts, progesterone levels quickly fall.

At the same time, prostaglandin levels increase to help the uterus contract and shed its lining.

Unfortunately, these prostaglandins don't always stay focused on the uterus.

They can also encourage the muscles of your intestines to contract, speeding up digestion and leading to:

• Loose stools
• Frequent bowel movements
• Urgency
• Mild diarrhoea
• Cramping

For many women, these digestive symptoms are most noticeable during the first one or two days of their period, when prostaglandin levels are at their highest.

Why Do Some Women Experience It More Than Others?

You may have friends who never experience period diarrhoea while you seem to deal with it almost every month.

That's completely normal.

Several factors can influence how strongly your digestive system responds, including:

• Natural prostaglandin production
• Individual hormone sensitivity
• Existing digestive conditions like IBS
• Endometriosis
• Stress levels
• Diet and hydration
• Genetics

Your symptoms may also change over time. It's not unusual for menstrual symptoms to become milder or stronger during different stages of life.

Other Digestive Symptoms You May Notice During Your Period

Period diarrhoea isn't the only digestive symptom that hormones can cause. In fact, many women experience a combination of gastrointestinal (GI) symptoms throughout their menstrual cycle.

If you've ever wondered why your stomach feels "off" during your period, you're not imagining it.

You may notice:

• Bloating – Feeling fuller than usual, even after eating small meals.
• Gas – Increased gas or burping caused by changes in digestion.
• Abdominal cramps – Sometimes it can be difficult to tell whether the pain is coming from your uterus or your intestines.
• Nausea – Some women feel slightly queasy, particularly if they experience severe cramps.
• Changes in appetite – Hormonal fluctuations can leave you craving carbohydrates, salty foods or sweets.
• Urgency – Feeling like you need to rush to the bathroom with very little warning.

These symptoms often improve naturally once your hormone levels begin to stabilise later in your period.

The important thing to remember is that your digestive system and reproductive system don't work independently of one another—they're closely connected, and hormonal changes can influence both.

Did You Know?

Your uterus and intestines share many of the same smooth muscle cells and nerve pathways within the pelvis. This is one reason menstrual cramps and digestive discomfort often occur together.

Why Do Some Women Get Constipated Before Their Period?

While some women experience diarrhoea during menstruation, others notice the exact opposite in the days leading up to their period.

If you've ever felt bloated, sluggish or constipated before your period starts, you can thank progesterone.

During the second half of your menstrual cycle, progesterone rises to prepare your body for a possible pregnancy.

One of progesterone's effects is relaxing smooth muscles throughout the body—including those in your digestive tract.

As your intestines slow down:

• Food stays in your digestive system for longer.
• More water is absorbed from your stool.
• Bowel movements become less frequent.
• Stools may become harder and more difficult to pass.

Then, when your period begins, progesterone levels fall while prostaglandins rise.

For many women, this creates a dramatic shift—from constipation one day to diarrhoea the next.

Although it can feel frustrating, this hormonal rollercoaster is a completely normal part of the menstrual cycle for many women.

What Actually Helps?

The good news is that there are several simple ways to support your digestive system while your hormones are doing their thing.

While you can't stop hormonal fluctuations entirely, you can often reduce discomfort by being kind to your body during your period.

1. Stay Hydrated

Diarrhoea causes your body to lose fluids more quickly than usual, increasing your risk of dehydration.

Drinking plenty of water throughout the day helps replace lost fluids and supports healthy digestion.

If you're experiencing frequent diarrhoea, you may also benefit from an electrolyte drink to replace important minerals like sodium and potassium.

A simple way to check your hydration is to look at the colour of your urine—it should be a pale yellow rather than dark or concentrated.

2. Choose Gentle Foods

When your stomach feels unsettled, bland foods are often easier to digest.

Many women find relief by choosing foods such as:

• Bananas
• White rice
• Oats
• Toast
• Applesauce
• Plain potatoes
• Vegetable soup
• Crackers
• Plain pasta
• Boiled chicken

These foods are generally gentle on the digestive system while helping you maintain your energy.

Rather than eating three large meals, try eating smaller portions more frequently throughout the day if your stomach feels sensitive.

3. Foods That May Help During Period Diarrhoea

Some foods naturally support digestion while replacing nutrients your body may be losing.

Consider including:

• Bananas (rich in potassium)
• Oats (contain soluble fibre)
• Plain yoghurt with live cultures (if dairy agrees with you)
• Sweet potatoes
• Rice
• Lean chicken
• Eggs
• Bone broth or vegetable broth
• Cooked vegetables rather than raw salads
• Herbal teas

Remember, everyone's digestive system is different. Pay attention to which foods leave you feeling better and which seem to make your symptoms worse.

4. Foods That Can Make Symptoms Worse

Certain foods can stimulate your digestive system even further.

If you're already dealing with period diarrhoea, you may want to limit:

• Spicy foods
• Greasy or fried meals
• Alcohol
• Large amounts of caffeine
• Sugary drinks
• Highly processed foods
• Artificial sweeteners if you're sensitive to them

This doesn't mean you can never enjoy these foods—it simply means your digestive system may appreciate a gentler approach during the first few days of your period.

5. Try Ginger or Peppermint Tea

Warm herbal teas can be surprisingly soothing when your stomach feels unsettled.

Many women find that:

• Ginger tea may help reduce nausea and support digestion.
• Peppermint tea may help relax the digestive tract and ease bloating.

Sipping something warm can also feel comforting during a day when your body simply isn't feeling its best.

6. Gentle Movement Can Help

When cramps and digestive symptoms strike, staying on the sofa all day can feel tempting.

But gentle movement may actually help.

A short walk around the block, light yoga or gentle stretching can:

• Encourage healthy digestion
• Reduce bloating
• Improve circulation
• Release endorphins that naturally ease discomfort
• Help relieve stress

You don't need an intense workout—sometimes 15 to 20 minutes of gentle movement is enough to make a noticeable difference.

7. Heat Therapy Isn't Just for Cramps

A hot water bottle or heating pad is often associated with period cramps, but it may also help relieve abdominal discomfort caused by bowel spasms.

The warmth helps relax muscles and can provide a comforting sense of relief when your lower abdomen feels tense or crampy.

Many women find that combining heat with a warm cup of herbal tea creates the perfect self-care ritual during the first day or two of their period.

8. Listen to Your Body

Perhaps the most important piece of advice is the simplest.

Your body is working incredibly hard during menstruation.

If you're feeling tired, rest.

If you're thirsty, drink water.

If you're hungry, nourish yourself with foods that make you feel good.

If you need to slow down for a day or two, that's okay too.

Your period isn't a sign that your body is failing you—it's a reminder that your body is doing exactly what it was designed to do.

Showing yourself a little compassion during this time can make both the physical and emotional experience of your period much easier to manage.

Could It Be Something Else?

While occasional period diarrhoea is completely normal, severe or persistent digestive symptoms shouldn't automatically be blamed on your menstrual cycle.

Sometimes your period can make an existing digestive condition more noticeable.

Conditions that may cause or worsen digestive symptoms include:

• Irritable Bowel Syndrome (IBS) – Many women with IBS find that symptoms flare during their period.
• Endometriosis – Endometrial-like tissue growing outside the uterus can affect the bowel and cause painful bowel movements, diarrhoea or constipation during menstruation.
• Inflammatory Bowel Disease (IBD) – Conditions such as Crohn's disease or ulcerative colitis may worsen during hormonal changes.
• Food intolerances – Lactose, gluten or other food sensitivities may become more noticeable during your period.
• Gastrointestinal infections – If diarrhoea is accompanied by fever, vomiting or persists well beyond your period, it may have another cause.

If your symptoms are unusually severe, happen every month without relief, or interfere with your daily life, it's worth discussing them with your healthcare provider.

When Should You See a Doctor?

While period diarrhoea is usually a normal response to hormonal changes, there are times when digestive symptoms shouldn't simply be dismissed as "just part of your period."

It's a good idea to speak to your healthcare provider if you experience:

• Blood in your stool
• Severe or worsening abdominal pain
• A fever or signs of infection
• Diarrhoea that lasts several days after your period has ended
• Symptoms of dehydration, such as dizziness, extreme thirst or very dark urine
• Unexplained weight loss
• Severe diarrhoea that happens every month and interferes with your daily life
• Painful bowel movements, especially if they worsen during your period

These symptoms could indicate another underlying condition, such as Irritable Bowel Syndrome (IBS), endometriosis, inflammatory bowel disease (IBD), food intolerances, or a gastrointestinal infection.

If you're ever unsure, it's always worth checking in with your doctor. Understanding what's normal for your body is an important part of caring for your health.

Did You Know?

Your digestive symptoms may actually be one of the first signs that your period is about to start.

Many women notice changes in their bowel habits 12 to 24 hours before bleeding begins, simply because prostaglandin levels start increasing before menstruation officially starts.

Once hormone levels begin to settle later in your period, digestive symptoms often improve naturally too.

Frequently Asked Questions

Is diarrhoea normal during your period?

Yes. For many women, diarrhoea during menstruation is completely normal. Hormone-like chemicals called prostaglandins can stimulate both the uterus and the intestines, causing bowel movements to become more frequent or looser than usual.

Why do I poop so much on my period?

During your period, prostaglandins help your uterus contract to shed its lining. Unfortunately, they can also stimulate your bowel muscles, speeding up digestion and increasing the need to use the bathroom.

Why do my period cramps get better after I poop?

Your uterus and bowel sit close together in your pelvis and share many nerve pathways. Having a bowel movement can temporarily reduce pressure in the pelvic area, making cramps feel less intense for some women.

Why am I constipated before my period but get diarrhoea afterwards?

This is one of the most common digestive patterns during the menstrual cycle.

Before your period, rising progesterone slows digestion, often leading to constipation. Once your period begins, progesterone falls and prostaglandins increase, causing the bowel to speed up.

Can stress make period diarrhoea worse?

Yes.

Stress can affect your digestive system at any time of the month, and during your period it may make bowel symptoms feel even more noticeable.

Finding ways to relax, prioritising sleep and staying hydrated may help reduce both stress and digestive discomfort.

Can a menstrual cup cause diarrhoea?

No.

A correctly positioned menstrual cup sits inside the vagina and does not enter the digestive tract.

However, because the vagina and rectum are close together, some women may feel more aware of pelvic pressure while adjusting to a menstrual cup. This should not cause diarrhoea.

How long does period diarrhoea usually last?

For most women, digestive symptoms improve within the first one to three days of their period as prostaglandin levels begin to decrease.

If diarrhoea continues well after your period has ended, it's worth speaking to your healthcare provider.

A Little Note From Me

For years, I genuinely believed I was just unlucky.

Every month, like clockwork, I'd find myself making more trips to the bathroom and wondering why my body seemed to have a mind of its own.

Learning that there was a scientific explanation for period diarrhoea completely changed the way I looked at it.

Instead of feeling frustrated or embarrassed, I realised my body wasn't working against me—it was simply responding to the natural hormonal changes that happen during every menstrual cycle.

I hope understanding the "why" behind period poops helps you feel a little kinder towards your own body too.

Sometimes knowing that something is normal can be just as comforting as knowing how to manage it.

The Bottom Line

If you've ever experienced diarrhoea during your period, you're certainly not alone.

Hormonal changes—particularly the release of prostaglandins—can affect both your uterus and your digestive system, making loose stools, urgency and stomach cramps surprisingly common during menstruation.

The good news is that these symptoms are usually temporary and often improve within a day or two.

Simple strategies like staying hydrated, choosing gentle foods, drinking herbal tea and giving yourself permission to slow down can make a real difference.

And remember: if your symptoms are severe, persistent or affecting your quality of life, don't hesitate to seek medical advice.

Your period shouldn't stop you from living your life—and understanding your body is one of the first steps towards feeling more confident and in control of your menstrual health.

Period Care That Works With Your Body

At Flo Angel, we believe periods shouldn't hold you back.

While a menstrual cup won't prevent period diarrhoea, it can make the rest of your period feel simpler, more comfortable and more sustainable.

Unlike pads and tampons, a menstrual cup collects rather than absorbs menstrual flow, offering up to 12 hours of leak-free protection, depending on your flow.

That means fewer bathroom stops to manage your period—even if your digestive system is keeping you busy.

Whether you're at work, travelling, exercising or simply relaxing at home, Flo Angel helps you focus less on your period and more on living your life.

Ready to experience a more comfortable period? Explore the Flo Angel Menstrual Cup collection and discover a reusable solution that's better for you—and for the planet.

References

·         ACOG: FAQs Dysmenorrhea: Painful Periods

·         Cleveland Clinic: Here’s the Deal with Period Poops

·         Mayo Clinic: Menstrual Cramps

·         IFFGD: https://iffgd.org/

·         NHS: Periods