Skip to content

The Weird Reason You Always Get Diarrhea Or Constipation During Your Period

Stephanie Eckelkamp
Author: Medical reviewer:
Updated on May 23, 2022
Stephanie Eckelkamp
Contributing Health & Nutrition Editor
By Stephanie Eckelkamp
Contributing Health & Nutrition Editor
Stephanie Eckelkamp is a writer and editor who has been working for leading health publications for the past 10 years. She received her B.S. in journalism from Syracuse University with a minor in nutrition.
Wendie Trubow, M.D., MBA
Medical review by
Wendie Trubow, M.D., MBA
Functional Medicine Gynecologist
Wendie Trubow is a functional medicine gynecologist with almost 10 years of training in the field. She received her M.D. from Tufts University.

Unfortunately, the topic of period poop isn't quite as easy to commiserate over as cramps and mood swings, so no one really addresses it.

But we're here to tell you these cyclical changes in your bowel movements that crop up just before or during your menstrual cycle are actually pretty common, thanks to shifting levels of hormones and hormone-like substances in the body. Fortunately, there are ways to make this unpleasant side effect less severe. Let us explain.

Advertisement
This ad is displayed using third party content and we do not control its accessibility features.

What causes period poop?

Some women may experience abnormal bowel function while on their period. Though the research isn't quite clear as to why this occurs, studies show it may be due to hormone fluctuations.

How shifting hormones can mess with period poop

Period diarrhea

One way your bowel movements may change during your period: diarrhea. "Period diarrhea is often caused by elevated prostaglandins," says Jolene Brighten, N.D., functional naturopathic medicine doctor and mbg Collective member.

These hormone-like molecules are released as the lining of your uterus breaks down before and during your menstrual cycle.

Prostaglandins are what cause the muscles of the uterus to contract and push out the uterine lining during menstruation—but when there is an imbalance in prostaglandins, this can also cause the contraction of the muscles in your bowels, causing you to poop more and experience diarrhea, Brighten explains. (Prostaglandins are also responsible for period cramps.)

Advertisement
This ad is displayed using third party content and we do not control its accessibility features.

Period constipation

Some women, on the other hand, may experience constipation. Between ovulation and the time you get your period, there's an increase in the hormone progesterone, which relaxes the muscles of your digestive tract. If levels of progesterone are elevated, then bloating, gas, and constipation can result, explains Brighten.

Basically, your digestive tract is so relaxed that it doesn't contract and push out waste as it normally would, leaving things to stagnate.

Period poop odor

As for a potentially strange smell, "Often poop is mixed with period blood and that can have a different odor," says double board-certified integrative physician Amy Shah, M.D.

Advertisement
This ad is displayed using third party content and we do not control its accessibility features.

How to prevent period diarrhea or constipation

The good news: You're not totally at the mercy of your hormones. Focusing on the right foods and specific nutrients can help get you prevent unwanted period poop, and get your digestive system back on track.

Because prostaglandins are synthesized from omega fatty acids, shifting your diet to contain more omega-3 fatty acids (from fatty fish like salmon and sardines, flaxseeds, chia seeds, hemp seeds, walnuts, or an omega-3 supplement) and fewer omega-6 fatty acids (found in vegetable oils and many processed foods) can lessen their effect and help prevent diarrhea, says Brighten.

While it doesn't specifically address the prostaglandin aspect of period diarrhea and constipation, incorporating a high-quality probiotic supplement regularly can help support healthy digestion, says Shah.*

A 2015 research review even found that some probiotic strains were able to lessen the duration of diarrhea symptoms by a day.

For managing both diarrhea and constipation, fiber is also a must. "Aiming to eat at least 25 grams of fiber daily can support healthy bowel movements," says Brighten.

Soluble fiber (found in chia seeds, flaxseeds, oats, oat bran, barley, beans, lentils, psyllium, and most fruits—especially berries) can help combat diarrhea by bulking up stool; while insoluble fiber (found in fruit and vegetable skins, wheat, wheat bran, rye, and rice) may be particularly beneficial for alleviating constipation.

mbg Tip

Soluble fiber found in chia seeds, flaxseeds, oats, oat bran, barley, beans, lentils, psyllium, and berries and insoluble fiber found in fruit and vegetable skins, wheat, wheat bran, rye, and rice, can support healthy bowel movements.
Advertisement
This ad is displayed using third party content and we do not control its accessibility features.

When to see your doctor

Of course, if these steps don't help, and you're having significant digestive distress at other times of the month as well, be sure to talk to your doc to rule out a more serious health condition like irritable bowel syndrome (IBS).

If during your period your BMs are very painful (out of ordinary), you're not able to keep food or drink down, or you develop vomiting, Shah says it's important to see your doctor immediately. 

The takeaway

Ultimately, abnormal period poop is actually quite normal. If you're experiencing uncomfortable diarrhea or constipation, there are some ways you can help prevent it through supplements and dietary changes.

Editor's Note: This article was originally published on March 28, 2019. A previous version of this article indicated that the hormone progesterone increases during your period. We have since clarified this statement to indicate that the hormone progesterone increases between ovulation and the time you get your period.

Stephanie Eckelkamp
Stephanie Eckelkamp
Contributing Health & Nutrition Editor

Stephanie Eckelkamp is a writer and editor who has been working for leading health publications for the past 10 years. She received her B.S. in journalism from Syracuse University with a minor in nutrition. In addition to contributing to mindbodygreen, she has written for Women's Health, Prevention, and Health. She is also a certified holistic health coach through the Institute for Integrative Nutrition. She has a passion for natural, toxin-free living, particularly when it comes to managing issues like anxiety and chronic Lyme disease (read about how she personally overcame Lyme disease here).