Whether you’re trying to conceive or you’re absolutely not interested in being pregnant but nervous you might be, you may look up every single thing going on with your body to see if it’s a possible sign of pregnancy. As health writers, we Google this stuff, too, which is how we realized there’s a lot of curiosity out there about whether diarrhea is a signal that you have indeed conceived. But is something as simple as diarrhea really a sign of early pregnancy? Here’s what experts have to say about this one.
Let’s go over what causes diarrhea in the first place, because that obviously plays a huge role here.
Basically everyone has experienced the loose, liquidy, way-too-frequent stools characteristic of diarrhea at some point. When you do have diarrhea, it’s normal for the crappy experience to last for up to two days, the Mayo Clinic says.
So, what’s occurring in your body to make your butt expel its contents so violently? Once the food you eat hits your stomach, that powerful organ mixes in some digestive juices and works it all into a thin liquid, according to the U.S. National Library of Medicine. That liquid moves to the rest of your digestive tract, which saps much of the fluids from this mixture and solidifies it, creating the poop that winds up in your toilet bowl.
Diarrhea happens because your small intestine (where most of your digestion happens) and/or colon (the longest section of your large intestine, charged with tasks like pushing stool along so it can exit your body) don’t properly absorb these fluids, Rudolph Bedford, M.D., a gastroenterologist at Providence Saint John’s Health Center in Santa Monica, California, tells SELF. Any health issue that disrupts their ability to do their jobs, like Crohn’s disease, or that pushes poop through your system more quickly than normal can cause diarrhea, he explains.
Interestingly enough, pregnancy hormones make constipation a more likely poop problem if you’re expecting, not diarrhea. Here’s why.
If you have a regular menstrual cycle (as in, you don’t have any health conditions that are throwing it off course and you’re not using birth control to suppress ovulation), your body starts to produce more of the hormone progesterone after you ovulate, which is usually mid-cycle.
Progesterone is a hormone that helps support pregnancy by thickening your uterine lining.
If you’re not pregnant, your levels of progesterone will increase until the week before your period, after which they’ll start to fall. If you are pregnant, your levels of progesterone will continue to increase after ovulation, Mary Rosser, M.D., Ph.D., an ob/gyn at NewYork-Presbyterian/Columbia University Irving Medical Center, tells SELF.
The thing about progesterone is that it’s a smooth muscle relaxant, meaning it makes the muscles in your body—including your uterus and intestines—slacken more than usual. As a result, your small intestine and colon may not contract as hard to push poop through your body, so you can end up constipated when you have more progesterone than usual coursing through your system, G. Thomas Ruiz, M.D., an ob/gyn at MemorialCare Orange Coast Medical Center in Fountain Valley, California, tells SELF. That includes the time after ovulation up until around a week before your period arrives, and, of course, during pregnancy.
Diarrhea, on the other hand, is more likely to happen as a function of your period, not pregnancy.
So, remember, if you’re not pregnant, your progesterone levels fall in the week-ish before your period is due. That means the muscles in your GI tract are no longer under progesterone’s muscle-relaxing spell, so your poop might just be normal. Or you could actually get period-induced diarrhea.
Your period can cause diarrhea because of prostaglandins, hormone-like substances from the cells in the lining of your uterus. These prostaglandins make your uterus contract to shove out your uterine lining when you menstruate, but they can also travel to the muscle lining your bowels and work their magic there. This can force your intestines to contract more intensely or frequently, possibly leading to diarrhea, Dr. Rosser says.
Of course, this doesn’t mean you won’t have diarrhea if you’re pregnant. You certainly can, it’s just not a clear sign of an early pregnancy.
Being pregnant means that your body is in an immunocompromised state, and that can make you more susceptible to infections than you would normally be. Given that, it’s possible that you could have diarrhea in early pregnancy from getting a stomach bug that your body would normally be able to fend off with no problem, Dr. Rosser says. Or, she points out, you could just eat something funny that would cause diarrhea regardless of whether or not you were pregnant.
The bottom line is that looking at diarrhea as an early sign—or not—of pregnancy is kind of like trying to read tea leaves, Dr. Ruiz says. Basically, you’re going to see what you want to see. “Diarrhea is not a good or reliable sign of early pregnancy,” Dr. Rosser says. Few things are, which is why—even though it’s tempting to interpret every weird body thing as a sign that you’re expecting—a missed period and positive pregnancy test are really the best indicators that you might be pregnant.