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

Dear Reader and Regulated,

You may be on to something in noticing the connection between hormones during the menstrual cycle and how it affects the digestive system. It’s understandable that you’re experiencing some monthly digestive confusion — it’s common to experience constipation or diarrhea just before or during menses. While research hasn’t pinpointed one singular cause of this effect, there’s some evidence supporting the link to hormones and hormone-like compounds.

A couple of investigations noted a hormonal link to period-related gastrointestinal woes. Both estrogen and progesterone (hormones released while a person menstruates) have been identified as potential causes of constipation. It’s also been found that prostaglandins, a fatty acid responsible for relaxing smooth muscle tissues at the onset of a period, can sometimes cause inflammation and diarrhea.

Another study showed a potential link between emotional symptoms, such as depressed mood and anxiety, and stomach symptoms. It’s also possible for existing GI conditions to be exacerbated at certain times of the menstrual cycle. In fact, research shows that people with irritable bowel syndrome (IBS), or a similar type of inflammatory bowel disease (IBD) such as Crohn's disease or ulcerative colitis, are more likely to experience digestive disturbances during their periods compared to individuals without chronic bowel conditions. That’s not to say that those who experience GI inflammation during their period have IBD or IBS, but it's something to ask a health care provider about if your symptoms seem extreme.

While there’s no clear treatment for these symptoms, there are a few actions you can try that might reduce your discomfort:

• Practice stress management strategies: If your discomfort is exacerbated by IBS, practicing relaxation techniques, such as meditation and yoga, physical activity, and getting enough sleep might help to reduce GI symptoms.
• Consider food choices around menses: Mild symptoms might be controlled through small changes to your dietary choices. Eating foods with plenty of fiber, such as fruits and vegetables, can help you to maintain routine bowel movements. 
• Keep a GI journal: In the days before your period, you may want to keep a journal to track your symptoms, the food you’re eating, physical activity, and any other factors that you think might be relevant. That way, you can look out for patterns and potentially sort out the culprit that’s causing your bathroom blues, and if needed, share with a health care provider.
• See a health care provider: If you notice that your symptoms are severe or difficult to manage, it may be a good time to consult with a medical provider. They might prescribe fiber supplements, laxatives, anti-diarrheal and anticholinergic medicine (which affect the nervous system), or they could focus on an underlying emotional issue and prescribe antidepressants or anti-anxiety medication. They may also help diagnose whether your monthly discomfort is a symptom of an underlying condition, such as endometriosis or IBS.

While the root cause of period-related GI issues is still somewhat elusive, it’s common. With a bit of investigation, you might be able to find a plan of action that allows you to sail through your pre-menses and period scot-free!