Why do my bowel movements change when I get my period?

Dear Reader and Regulated,  

If you’ve ever noticed that your bathroom habits are a little different around your period, you’re not imagining things. Constipation, diarrhea, and other changes in bowel movements are common during menstruation. The culprit is usually hormones. Read on to learn about how your digestive system and menstrual cycle are connected. With this new information, maybe you’ll be a bit more comfortable when the crimson wave rolls in. 

How are your bowel movements and periods connected?  

Right before your period starts, the lining of your uterus (called the endometrium) starts to change. This lining is where a fertilized egg would implant if pregnancy occurs. When that doesn’t happen, the lining sheds, and that’s what causes your period. 

As your body gets ready for this shedding process, the cells in your uterine lining start making more prostaglandins (fatty compounds that act similarly to hormones). These compounds tell the smooth muscles in your uterus to contract so the lining can get released. Sometimes, though, your body makes more of these chemicals than needed. When that happens, they can spill over into your bloodstream and affect other smooth muscles, like the ones in your intestines. This can contribute to faster gut movement, looser stools, and maybe more trips to the bathroom than usual.   

However, some people also find that they’re more constipated during their period, which can also be attributed to the sex hormones.  

What role do hormones play in this process? 

Estrogen, which is one of the primary sex hormones, influences how strongly you feel pain. During your period, estrogen levels are at their lowest, which reduces your pain tolerance. The reason behind this is that estrogen boosts the production of serotonin, which is basically a “happy” hormone. During the follicular phase, which is typically 6 to 14 days after your period, estrogen increases. A rise in estrogen can help get rid of period pain, so your stomach aches and cramps won’t hurt as much.  

Progesterone is another hormone worth reviewing. This sex hormone’s job is to thicken your uterine lining in preparation for a possible pregnancy. During the luteal phase (the days leading up to your period), progesterone levels climb. High progesterone can slow digestion and trigger weird food cravings—hello, chocolate, and ice cream! Changes in what (or how) you eat can leave you feeling gassy or noticing that your poops are smellier than usual. When you’re actually on your period, progesterone drops to its lowest level, and your food cravings fade along with it. 

Additionally, both estrogen and progesterone play a role in how quickly food moves through your digestive system. They can affect the smooth muscle contractions, and when these hormones decrease, they may lead to constipation. Given the complexity of these systems, some people may have varying experiences during their period. Some may feel more constipated, while others have more bowel movements than they usually would.  

How can you ease changes in your bowel movements during your period? 

If your poops tend to feel “stuck” during your period, a few lifestyle tweaks can help. Eating more fiber, staying hydrated, and exercising can all encourage things to keep moving. Cutting back on processed foods and refined sugar may also reduce bloating and discomfort. 

If constipation still won’t budge, some providers recommend a gentle over-the-counter laxative, but it may be best to use those sparingly. Keep in mind that constipation, reflux, and bloating can vary significantly depending on where you are in your menstrual cycle. 

For people with painful periods (also called dysmenorrhea), digestive symptoms like nausea, diarrhea, or even vomiting can feel more intense. Hormonal shifts can also aggravate digestive conditions like irritable bowel syndrome (IBS) by increasing inflammation in the body. Whether or not you have a diagnosis, it may be a good idea to speak with a health care provider if period-related digestive issues are disrupting your daily life. 

Being on your period and dealing with all the symptoms that come with it can be a real drag. Hopefully, understating what’s going on behind the scenes helps you feel a little more in control of your body and better prepared to manage any digestive comfort that pops up each month.  

To smooth sailing ahead,