Oh, prostaglandins. 

These chemicals stimulate the smooth muscles in your uterus and they amp up production just before your period begins in order to help the uterus contract and shed its lining each month. Turns out your uterus and large intestines are kind of like neighbors, so what happens in one can impact the other.

Here are some common experiences you may have during toilet time while on your period (and why!):

More Poop ✅

If your body produces more prostaglandins than it needs, they’ll enter into your bloodstream and have a similar effect on other smooth muscles in your body, like in your bowels. The result: more poop. 

Diarrhea! Why?!

Excess prostaglandins can also give you diarrhea. And if you’re a coffee drinker, that could make it worse because coffee has a laxative effect (even if it’s decaffeinated). You can try cutting back or eliminating coffee for a period of time if you find it makes your diarrhea worse. If you gasped at the idea of that, or cutting coffee simply doesn’t do it, then focus on drinking lots of water to prevent dehydration.

The smell, though… 

That feeling that you want to eat all of the things closer to your period, aka compulsive eating, is linked to higher levels of progesterone during the premenstrual phase. Changes in your eating habits are what can cause foul-smelling poop and farts. It’s harmless, but if it bothers you, resisting the urge to overeat and avoiding refined sugars and processed foods should do the trick.

Ugh, constipation. 

Low levels of prostaglandins and high levels of progesterone can slow digestion and make your poop go MIA. Upping the fiber in your diet, exercising, and drinking plenty of water can help to keep things moving. If you’re really stuck, a gentle over-the-counter laxative or stool softener can also help.

It actually hurts to poop on my period.

First, we’re sorry, that sucks. This could be happening for a few different reasons. First, menstrual cramps can actually feel worse when you strain to poop. Then there’s diarrhea, which is known to come with stomach cramps. Finally, certain gynecological conditions such as endometriosis or ovarian cysts could be the culprit.

Cramps vs. Feeling the Need to Poop — which is it?

We can’t say for sure, but remember what we said earlier about uterine and bowel contractions? Since they’re both caused by prostaglandins it can be hard to tell the difference between the two. Also, don’t underestimate cramps, they’ve been known to cause pressure in the pelvis, low back, and even the butt.