Factors that can contribute to diarrhea in early pregnancy

Your first prenatal appointment often includes a urine pregnancy test and an internal exam. The doctor or midwife will check to make sure you’re pregnant and check on the health of your uterus and ovaries. At some point, your care provider is likely to want to know if you’ve had any pregnancy symptoms, such as nausea or vomiting constipation, diarrhea, bleeding, or pain.

One common symptom that many women report during pregnancy is diarrhea. Some women may even begin having loose stool during the first trimester (the three months of the 40 weeks of gestation) before they know they are pregnant. Many factors can contribute to diarrhea in early pregnancy including:

Hormonal changes

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Hormones play a large role in digestive health and function. A pregnant woman’s body is already undergoing a lot of hormonal changes, and these changes tend to cause the digestive system to slow down in the first trimester. This can start as early as two weeks after conception and may last through week 20. As such, many pregnant women experience loose stools in early pregnancy.


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If you’re constipated or your stools are hard and dry, they can be more difficult for the body to move through the digestive tract and pass out of the body. Increased progesterone (which relaxes smooth muscles) and slower transit time (the speed at which food moves through the digestive system) may lead to easy bowel movements that occur too frequently. As a result, diarrhea can become a common symptom during pregnancy.


Many women complain about heartburn during pregnancy due to changes in hormone levels that relax the sphincter between the stomach and esophagus. This allows acid from the stomach to flow up into the esophagus, where it may cause burning and discomfort.

Pregnancy-related changes

While most women make enough pregnancy-safe digestive enzymes to break down food without difficulty while pregnant, some women have a deficiency in these enzymes that can result in diarrhea. In addition, many women report some degree of loose stools during early pregnancy due to pressure from a full bladder pushing on the bowel, which is common when the uterus expands later in pregnancy.

Consuming too much caffeine

Caffeine tends to speed up transit time through the digestive tract. It also seems to increase peristaltic contractions (muscle contractions in the intestines) more than usual. These effects add up to an uncomfortable situation for some women, who find themselves having diarrhea after drinking even a small amount of caffeine.

More than one factor

Any one of these factors can cause constipation, which in turn causes loose stool and diarrhea. Other causes may be an imbalance in your digestive tract’s bacteria or yeast levels (dysbiosis), a food allergy, or a parasite infection. If you have diarrhea in early pregnancy due to more than one contributing factor, it is especially important to determine the underlying cause so that you can be sure you’re getting relief from the discomfort and not harming your baby.


Diarrhea during pregnancy is a common problem. Some causes of diarrhea in early pregnancy are hormonal changes, constipation, heartburn, and certain foods or beverages. It’s important to figure out the underlying cause so that you can get relief from symptoms without harming your baby.

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