Column: How women's periods can affect their bowels

Dr Amanda Chay ND
By Dr Amanda Chay ND
May 29th, 2019

Hormones are the cause of digestive changes or discomfort for many women during their period. Changes in Estrogen and Progesterone before your period starts will cause symptoms such as bloating and constipation.  Other women experience diarrhea before or once their period starts and this is due to increased prostaglandins, a type of lipid that increases inflammation, causing uterine contractions.

A normal cycle is anywhere from 21 to 35 days, with the average being 28 days.  The first fourteen days of your cycle (or until you ovulate) is your follicular phase, and the second half (from ovulation until your period starts) is the luteal phase.

Day one of our periods is the first day where we have a heavy flow (spotting is not counted as day one). After day one, your estrogen slowly starts to increase anywhere from 7-21 days (depending on the length of your cycle), until a hormone called leuteinizing hormone (LH) spikes, making your estrogen to drop and causing ovulation.  At this point in the cycle women may feel one-sided lower abdominal pain that is called ‘mittelschmerz’ and is due to an ovary releasing an egg (ovulation).

After ovulation, our progesterone starts to rise in the luteal phase for 10-16 days, dropping a few days before our period starts.  During our luteal phase, progesterone should be higher than estrogen and if there is an imbalance this can cause PMS symptoms. This drop in progesterone at the end of the luteal phase is what causes our period to happen.  If we become pregnant, our progesterone stays high to keep the uterine lining thick throughout the pregnancy.

What does all of this have to do with hormones?

Progesterone, and also estrogen according to a mouse study1, slows your transit time, meaning your bowels contract less and move a lot more slowly, leading to constipation, gas, and bloating.  High levels of these hormones are also why pregnant women tend to be more constipated.  If your estrogen is too high, this will cause water retention and bloating (and weight gain!).

For women who experience diarrhea, prostaglandins are to blame.  Normal period pain is a bit of cramping in your lower abdomen or back, however if it is interfering with daily activities or strong enough that you need to take painkillers, this is not normal period pain. Prostaglandins increase right before and during our period to help our uterus contract and if they are too high this will cause cramping and pain.  Severe period pain that lasts for many days and causes you to miss out on work or fun activities is usually caused by medical conditions such as endometriosis or adenomyosis. 

Since prostaglandins cause smooth muscle contraction of the uterus, they can also affect the smooth muscle of the intestines around them, increasing contractions and causing diarrhea.  Women whose hormones are imbalanced and have higher estrogen and lower progesterone can also have higher prostaglandins, causing more period pain and loose stools. Women who have IBS often have worse symptoms around this time because of the increased prostaglandins and inflammation.

During your cycle, when might you start to notice these bowel

Constipation and bloating can start as soon as your progesterone starts to rise, anywhere from day 7 to 35 depending on your cycle. Some women will only notice changes a few days before their period, followed by relief once their period starts.  Most women with constipation will feel relief once their period starts.

For women who get cramping and diarrhea, this usually happens 1-3 days before their period starts or right when the period starts and lasts for a couple of days.

Is it normal to experience digestive issues like these during your period?  Is there any way to find relief?

While it may be typical, in my opinion it is not normal to experience extreme changes in digestion during your period. A slight bit of constipation or having an extra bowel movement or two once your period starts is okay, however if you are experiencing extreme cramping, bloating, diarrhea, and/or having less than one bowel movement per day this is not normal.

The good news it that as a Naturopathic Physician I help women with symptoms like this every day and know there are plenty of ways to find relief. The first step is to start tracking your period so you know how long your cycle is, how long your follicular and luteal phases are, and when you are ovulating.  Once you know this, it makes it easier to figure out which hormones may be out of balance.  There are many tell tale signs of hormone imbalance with PMS, for example, women with too much estrogen often experience breast pain, fluid retention, irritability, and headaches prior to their periods.

There are many herbs and supplements you use to balance hormones.  However, the easiest things you can do at home are the following:

·       Follow a Mediterranean diet (the Mediterranean decreases inflammation, helping with women who get cramps and diarrhea before their period.)

·       Eat 2 tbsp fresh ground flaxseed per day (this helps regulate estrogen and will increase fiber in your diet, keeping your bowels regular.)

·       Increase your probiotics (estrogen needs bacteria to move out of your body, so good gut health is key!)

·       Decrease inflammatory foods such as cow dairy and wheat (and all gluten grains for some people).  I try and have patients follow the 80:20 rule where 80% of the time (eg. throughout the week) you keep these out of your diet and 20% of the time (eg. the weekend) you can enjoy them.

·       Increase cruciferous veggies such as cabbage, cauliflower, broccoli and Brussels sprouts (these help balance estrogen).

·       Increase anti-inflammatory herbs in your diet such as turmeric and ginger (these help decrease inflammation caused by prostaglandins).

·       Avoid hormone disrupting chemicals found in plastic containers and non-natural makeup and lotions (such as those that contain parabens)



1.      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3823955/

2.      Period Repair Manual by Dr. Lara Briden, ND.

3.      https://gut.bmj.com/content/50/4/471

Categories: GeneralHealth

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