If you notice a change in the shape & texture of your poop before and during your period, it’s not just you – & there’s a reason for it (hint: it’s most likely your hormones)

Cramps, mood swings, tiredness – we already know that periods can be a messy and sometimes painful fact of life. But what’s less talked about is the changes in digestion that can occur around this time, like the unusual poops that might accompany our heavy bleeding.

If you experience constipation and/or diarrhoea around your time of the month, that’s no coincidence. According to Dr Ellie Cannon, author of Is Your Job Making You Ill?, this is typically down to the same hormonal fluctuations that occur during your period as they can also impact your digestion.

From its colour, size and texture, your poop says a lot about what’s going in your body. This is what you need to know about how it relates, more specifically, to your menstrual cycle.

Why do I get constipated before my period?

“Constipation often occurs during the luteal phase [the latter half of your cycle] just before period bleeding starts, which tends to be the result of rising levels of the hormone progesterone,” explains Dr Rumbi Mutenga, a GP and former midwife. “This might be accompanied by bloating and abdominal pain.”

If you’re in the habit of tracking your cycles, you may be able to spot a monthly pattern of premenstrual constipation, which can be helpful for seeing when it might affect you most, enabling you to plan how you might be able to reduce its effects.

Why do you poop more during your period?

Ever experienced premenstrual constipation, only to have loose stools and even diarrhoea once the bleeding starts? According to Dr Mutenga, this equally unglamorous problem is due to another compound your body starts producing called prostaglandin, which helps relax the muscles of the vaginal wall.

Unfortunately, it has the same effect on the bowel muscles, adds Dr Cannon: “That relaxing of the muscles is why, when you have your period, you tend to open your bowels more and poo more often.”

Research from the University Hospital of South Manchester has found that these unpleasant effects can be more pronounced in those with irritable bowel syndrome (IBS), with an increased frequency of bowel movements and greater abdominal pain and bloating when compared to most other phases of the menstrual cycle.

Why your poop may be softer during your period

It’s not just the frequency of your poops that changes during your period, but their texture.

If you’re constipated in the week before your period, you may produce harder or “pellet-like” stools, says Dr Cannon – while poops during your period may well be looser.

This is to do with the amount of time the poop stays in your bowel. Typically, it would stay in your bowel for 30 to 40 hours, during which time your gut absorbs nutrients and fluids from your stool. However, if you’re constipated, it will stay there for longer, which may cause it to be harder and more difficult for your body to expel.

Equally, if your bowels are relaxing due to the effect of prostaglandin, then your stools might be expelled more quickly than usual – meaning they’re softer and more watery, because your body hasn’t had the time to absorb the fluid.

Can a delayed period affect your digestion?

“If your period arrives later than expected, it may lead to prolonged digestive effects, such as constipation, as your progesterone levels remain raised”, says Dr Cannon.

However, this may not always be the case, as periods can be delayed for a number of different reasons, including weight loss, stress and pregnancy.

From constipation to loose stools – how to reduce menstrual-related changes in digestion

Before your period

In the week leading up to your period, adopting a few “effective self-care methods” may help you avoid constipation.

Dr Cannon suggests gentle exercise, drinking plenty of water and eating soluble fibre sources, such as fruit in all forms (whole, dried and juiced), which might help open the bowels. “Digestion is the type of issue that has multiple factors, so your diet can aggravate or improve hormone-related changes,” she says. 

If you’re feeling particularly ill due to constipation and the above lifestyle changes haven’t worked, an over-the-counter laxative product might be a short-term option to consider, adds Dr Cannon. ​​

There are a variety of different types to choose from, ranging from osmotic (ones that trap water in the bowel) to bulk-forming (fibre supplements) and stimulants (such as glycerol and senna that can help increase movement in the intestines). Your pharmacist will be able to guide you on the right one for you and your needs*. If your symptoms don’t improve or if you have persistent constipation, it’s a good idea to visit your GP.

Try: Boots Good Gut Daily Fibre

• 14 sachets

• Gluten-free

• Dairy-free

• Vegan-friendly

• Tropical flavour

Providing a low calorie source of extra fibre with a hint of tropical flavour, this daily food supplement helps you to achieve the UK government recommended daily fibre intake of 30g. It also contains calcium to support normal digestion.

During your period

While it’s tempting to fall into unhealthy eating patterns (like stocking up on milk chocolate), resisting the urge might help you deal with uncomfortable digestive side effects, such as the increased need to poop more during your period.

Maintaining a healthy, balanced diet instead of comfort eating and making small changes like swapping your morning coffee (which can have a laxative effect) for a glass of water or no-added-sugar squash or fruit juice (to reduce dehydration) could help.

Are your symptoms a little more extreme? “With regards to diarrhoea symptoms, it’s important to avoid foods that commonly worsen this condition, such as caffeine, dairy and fatty or spicy foods,” says Dr Mutenga. In most cases, diarrhoea should clear up within a few days without treatment and staying hydrated can help.

A longer-term solution, Dr Mutenga suggests, may be to use the hormonal contraceptive pill to help balance out hormone levels. “A lot of the symptoms are due to hormonal flux or spikes in particular hormones,” she says, “so one way of counteracting this is hormonal contraception, which may lead to more subtle changes and lessen symptoms.”

See your GP if you’re looking to learn more about the contraceptive pill, and whether it could be suitable for you, or you may wish to consider accessing the Boots Online Doctor Contraceptive Pill service**.

The takeaway

If you notice that your poops are harder just before your period and softer during your period, it’s not just you, it’s your hormones. Changes to their shape, colour and texture are common and totally normal, and there’s a range of lifestyle changes and over-the-counter treatments that may help reduce their effect on your day-to-day life.

However, if your symptoms are really bad or persistent, or if you experience bloating, book in with your GP who will be able to help you find ways to reduce them and see if there may be an underlying cause.

For more tips about gut health, check out our Q&A with Dr Megan Rossi, better known as The Gut Health Doctor. From why a bit of dirt might actually be good for us to how important fibre is for our gut health, her insights provide valuable food for thought.

*When using laxatives, make sure to take the manufacturer's recommended dose. Laxatives should only be used as a short-term solution, unless your doctor advises you otherwise.
**Access to prescription-only medicine is subject to an online consultation with a clinician to assess suitability. Subject to availability. Charges apply.