No need to be squeamish, toilet habits across your monthly cycle change and it’s perfectly normal. Now, the question is, why do I experience constipation before my period?


First things first, in order to determine when you start your premenstrual syndrome PMS you need to establish the length of your cycle. Your cycle starts on the first day of real flow, which means that residual spotting belongs to the previous cycle. Thus, “Cycle Day 1” is the first day you need protection. Your period can last 3 to 8 days and then wait for your cycle to start again to complete the loop. For example, if your period started on June 1st and your next period started June 29th, then the length of the period was 28 days. The length is calculated from Cycle Day 1 to the eve of the day you start bleeding again (you start a new cycle). The society of obstetricians and gynaecologists of Canada considers a normal period to come again every 21-35 days1.

All that being said, when does PMS occur? PMS starts during the third and final phase of the cycle called the luteal phase. Preceding the ultimate phase, an egg is released, it’s the ovulation, the period when a baby can be conceived. If fertilization does not occur the uterine lining will begin shedding around the 14th day of the cycle until the first day of the next menstrual period when it will be expelled.


Everyone poops but chances are it’s not your favorite subject to talk about and it hasn’t been addressed with your girlfriends. So let’s demystify what causes the bowel frequency to change during the woman’s cycle. As described previously, ovulation happens in the second phase of the cycle around day 14. This period is characterized by a rise in progesterone, a hormone that helps prepare the body for pregnancy3. If the egg is fertilized the levels of this hormone will keep increasing, however if it is not then the levels will drop around day 20 of the cycle right before bleeding begins.

Progesterone is the culprit as it is a muscle relaxant. In fact, the organs become so relaxed that the wave-like contractions of the digestive tract, called peristalsis, responsible for getting things moving down there, get a little lazy. As a result, you may experience constipation before getting your period.


  1. Try a Magnesium supplementation
  2. Give rye bread a try, it contains lactobacilli probiotics and helps relieve constipation4
  3. Eat plums (dried prunes) for a healthy bowel movement 5


This article is for information purposes only.


1-The society of obstetricians and gynaecologists of Canada. Menstrual Cycle Basics. Consulted online June 1st.

2-Emedicinehealth.PMS. Consulted online June 1st 2018

3- You and your hormones. Progesterone. Consulted online June 1st

4- Constipation Is Relieved More by Rye Bread Than Wheat Bread or Laxatives without Increased Adverse Gastrointestinal Effects, R Holma, S-M Hongisto, M Saxelin, R Korpela. The Journal of Nutrition, Volume 140, Issue 3, 1 March 2010, Pages 534–541.

5- Aliment Pharmacol Ther. 2011 Apr;33(7):822-8. doi: 10.1111/j.1365-2036.2011.04594.x. Epub 2011 Feb 15. Randomised clinical trial: dried plums (prunes) vs. psyllium for constipation. Attaluri A1, Donahoe RValestin JBrown KRao SSAliment Pharmacol Ther. 2011 Apr;33(7):822-8. doi: 10.1111/j.1365-2036.2011.04594.x. Epub 2011 Feb 15.