Diarrhea During Pregnancy: Causes, Is It a Sign of Pregnancy and When to Worry

Diarrhea during pregnancy is usually caused by a stomach bug, something you ate, a food intolerance, a medicine or hormone changes, and while most bouts pass in a few days, pregnant people should stay in touch with their provider and watch closely for dehydration.

Loose stools when you are expecting can be confusing. Is it the pregnancy, something you ate, or a sign that labor is coming? Diarrhea during pregnancy has many possible causes, and the right next step depends on what else you are feeling and how far along you are.

This guide covers whether diarrhea is a sign of pregnancy, why hormones can change your bowels, the common causes, what changes from the first trimester to the third, the Listeria risk, what helps, and the warning signs that mean you should call your provider right away.

Diarrhea During Pregnancy: The Short Answer

NIDDK defines diarrhea as loose, watery stools three or more times a day, or more often than what is normal for you. It can come with an urgent need to use the bathroom, cramping or pain in the abdomen, nausea and, at times, loss of control of bowel movements.

Cleveland Clinic sorts diarrhea by how long it lasts: acute diarrhea lasts a few days or less and usually goes away on its own, persistent diarrhea lasts two to four weeks, and chronic diarrhea lasts longer than four weeks or keeps coming back. Diarrhea that lasts beyond a few days in pregnancy is a reason to call your provider.

Is Diarrhea a Sign of Pregnancy?

Not a reliable one. Diarrhea is not on Mayo Clinic’s list of early pregnancy symptoms. That list includes a missed period, sensitive or swollen breasts, nausea with or without vomiting, needing to urinate more often, tiredness, mood swings, bloating, light spotting, mild cramping, constipation, changes in food preferences and a stuffy or runny nose.

Notice that constipation, not diarrhea, is the bowel change Mayo Clinic lists. It explains that hormonal changes cause your digestive system to slow down, which can lead to constipation, and that hormonal changes in early pregnancy can make you feel bloated. The sources we read do not list diarrhea as an early sign of pregnancy.

Mayo Clinic adds that many of these signs are not unique to pregnancy. Its advice: if you miss a period and notice symptoms, take a home pregnancy test or see your health care provider. Only a test or your provider can confirm a pregnancy. For timing, see our guides to hCG levels, implantation bleeding and 4 weeks pregnant.

Why Pregnancy Can Change Your Bowels

Your gut does not stay the same through pregnancy. A 2016 review on gastrointestinal diseases in pregnancy, published in Gastroenterology Clinics of North America, says that many disorders of the gastrointestinal tract are common in pregnancy. It describes two hormone effects that pull in different directions:

• Progesterone: elevated levels may change how the gut moves (its motility), which the review links to nausea, vomiting and reflux. Mayo Clinic connects the same slowing to constipation.
• Prostaglandins: the review says pregnancy-induced diarrhea may be due to elevated levels of prostaglandins.

That is why some people swing between constipation and looser stools. A change in diet can add to it. Many people eat differently in pregnancy. NIDDK notes that trouble digesting certain carbohydrates, such as lactose (milk sugar), fructose (fruit sugar), sucrose and sugar alcohols, can cause diarrhea.

When diarrhea comes on suddenly with vomiting, fever or cramps, do not assume it is “just pregnancy.” Check the causes below.

Common Causes of Diarrhea While Pregnant

Cleveland Clinic and NIDDK list the same main causes of diarrhea in adults. Pregnancy does not protect you from any of them.

Antacids are worth a second look. Reflux is one of the common pregnancy complaints the 2016 review covers, many people reach for antacids, and NIDDK lists antacids containing magnesium among the medicines that can cause acute diarrhea. If your stools loosened after you started taking an antacid or any new supplement, tell your provider and ask whether to switch. Do not stop a prescribed medicine on your own.

Diarrhea During Pregnancy by Trimester

The causes above can happen at any point. What changes is what else to watch for.

First trimester. This is when hormone shifts are newest, and when many people change what they eat because of nausea, food aversions or cravings. The 2016 review links pregnancy-induced diarrhea to prostaglandins, and Mayo Clinic lists bloating and constipation as early hormone-related changes, so your bowels may feel unpredictable for a while. If you are vomiting and have diarrhea at the same time, or cannot keep fluids down, call your provider, because you can lose fluid quickly. Our first trimester guide and 7 weeks pregnant page cover the other early changes.

Second trimester. The sources we reviewed do not tie diarrhea to the middle of pregnancy specifically. When it appears now, the everyday causes (a stomach bug, food poisoning, a food intolerance, a medicine) are the usual suspects.

Third trimester. Near term, loose stools can be one of the signs that labor is getting closer. Cleveland Clinic lists “loose stools or diarrhea” among other signs labor could be near, explaining that some of the hormones and medications that start labor can also stimulate your bowels. Diarrhea alone does not tell you labor is starting, and no source we read gives a set number of hours between diarrhea and labor. Watch for the other signs: regular contractions, cramps, pelvic pressure, a change in discharge and losing your mucus plug. Our guide to signs that labor is 24 to 48 hours away goes through each one.

Before 37 weeks the same symptoms mean something different. March of Dimes defines preterm labor as labor before 37 weeks of pregnancy and lists belly cramps, with or without diarrhea as one of its warning signs. The full list is in the red flags section below. March of Dimes says that if you have even one sign or symptom of preterm labor, call your health care provider right away.

Not sure whether you are feeling contractions or gas cramps? Our guide to what contractions feel like explains how to tell them apart and how to time them.

Listeria and Food Poisoning: Why Pregnancy Raises the Stakes

Food poisoning deserves extra respect in pregnancy. According to the U.S. Food and Drug Administration (FDA), pregnant women are about 10 times more likely to get listeriosis, the infection caused by Listeria bacteria, than other healthy adults.

The FDA lists listeriosis symptoms as fever, muscle aches, nausea, vomiting, diarrhea, headache, stiff neck, confusion, loss of balance and convulsions. A pregnant woman may have only mild, flu-like symptoms, or none at all, and symptoms can appear a few days or even weeks after eating contaminated food. The FDA says listeriosis can lead to miscarriage, premature labor, the delivery of a low-birth-weight infant or infant death. Its advice is direct: if you have any of these symptoms, see your doctor or health care provider immediately.

The FDA’s list of foods to avoid or handle carefully in pregnancy includes:

• Hot dogs, luncheon meats and cold deli meats, unless reheated until steaming hot.
• Unpasteurized (raw) milk and cheeses made from it.
• Soft queso fresco-type cheeses, even when made with pasteurized milk, unless heated until steaming hot.
• Refrigerated pates and meat spreads.
• Refrigerated smoked seafood, unless it is cooked.

Because symptoms can start weeks later, mention anything on that list you ate recently when you call.

Dehydration: The Main Risk to Watch

Cleveland Clinic calls dehydration the biggest potential complication of diarrhea and warns that, without treatment, severe dehydration can become life-threatening.

NIDDK lists these signs of dehydration in adults:

• Extreme thirst or a dry mouth.
• Urinating less than usual.
• Feeling tired, dizzy or lightheaded.
• Dark-colored urine.
• Skin that, when pinched and released, does not flatten back to normal right away.
• Sunken eyes or cheeks.

NIDDK says to see a doctor right away for symptoms of dehydration. A simple habit helps: check the color of your urine each time you go. If it is getting darker, or you are going much less often, call. Feeling dizzy or lightheaded is on NIDDK’s list too, so call rather than wait.

What Helps: Fluids, Food and Rest

Cleveland Clinic’s advice for mild diarrhea centers on fluids, easy foods and time. These steps come from its diarrhea guidance; check with your provider about anything that is not on your usual pregnancy plan.

• Drink fluids with electrolytes: Cleveland Clinic names oral rehydration solutions and broth.
• Sip slowly: if drinking upsets your stomach, take small sips throughout the day instead of large glasses.
• Eat small, frequent meals: rather than three big ones.
• Choose easy foods: Cleveland Clinic lists bananas, rice, applesauce and toast as easier to tolerate.
• Skip the irritants: Cleveland Clinic suggests avoiding caffeine, alcohol and greasy foods.
• Notice dairy and sweeteners: if milk, very sweet fruit juice or sugar-free products seem to set you off, NIDDK’s list of hard-to-digest carbohydrates (lactose, fructose and sugar alcohols) may explain why.
• Rest: let your body put its energy into recovering.

Ask your provider whether you should keep taking your prenatal vitamin while your stomach settles, and whether to take it with food.

Herbal teas are a common comfort drink, but not all are recommended in pregnancy. See our guide on chamomile tea during pregnancy before you brew a pot.

Can You Take Medicine for Diarrhea While Pregnant?

Ask before you take anything, including an over-the-counter product you used without thinking before you were pregnant. Here is what the sources we read say about specific options:

• Over-the-counter anti-diarrheals in general: Cleveland Clinic names loperamide and bismuth subsalicylate as over-the-counter options for adults, and says not to take over-the-counter diarrhea medicine if you have bloody diarrhea or a high fever unless a provider says it is safe. Its page does not address pregnancy.
• Bismuth subsalicylate: StatPearls, a National Institutes of Health (NIH) clinical reference, notes that the CDC recommends against using it to prevent or treat traveler’s diarrhea in pregnant women. StatPearls also says people allergic or sensitive to salicylates, including aspirin, should not use it. Ask your provider before taking any bismuth product while pregnant.
• Probiotics: Cleveland Clinic mentions probiotics only if your provider recommends them.
• Antibiotics: NIDDK lists antibiotics as a cause of diarrhea. If you get diarrhea while taking one, call the prescriber instead of stopping the course on your own.

We do not list doses here on purpose. Your provider knows your stage of pregnancy, your other medicines and the likely cause, and can tell you what is appropriate, if anything.

Before You Call: What to Note

A few details make the call faster and help your provider decide whether you need to be seen. Jot these down while you wait for a callback:

• How many weeks pregnant you are.
• When the diarrhea started and how many loose stools you have had today. NIDDK uses six or more loose stools in a day as a reason to see a doctor right away.
• Whether there is blood, pus or black, tarry stool.
• Fever, and your temperature if you have a thermometer.
• Vomiting, and whether you can keep fluids down.
• How often you are urinating and what color your urine is.
• Anything you ate in recent weeks from the FDA’s Listeria list, any recent travel, and anyone at home with the same illness.
• Later in pregnancy: contractions or cramps, pelvic pressure, fluid leaking, bleeding, and whether your baby is moving as usual.

Related Betteroo Guides

• First trimester guide
• Third trimester guide
• Signs labor is 24 to 48 hours away
• Implantation bleeding
• What do contractions feel like?
• Mucus plug

When to Call Your Provider

NIDDK says pregnant people who have diarrhea should keep in touch with their doctor, so calling early is never an overreaction. Call your provider right away if you have:

• Diarrhea lasting more than 2 days: NIDDK’s threshold for adults. Because NIDDK also says pregnant people should keep in touch with their doctor, you do not need to wait 2 days to call.
• Signs of dehydration: extreme thirst, dry mouth, urinating less, dark urine, dizziness or lightheadedness (NIDDK).
• A high fever: (NIDDK, Cleveland Clinic).
• Blood or pus in your stool, or black, tarry stools: (NIDDK).
• Severe pain in the abdomen or rectum: (NIDDK).
• Frequent vomiting, or six or more loose stools in a day: (NIDDK).
• Possible food poisoning or Listeria exposure: the FDA says to see your doctor immediately if you have listeriosis symptoms such as fever, muscle aches, vomiting, diarrhea or a stiff neck.
• Before 37 weeks: cramps with or without diarrhea: or any other preterm labor sign, such as regular contractions, pelvic pressure, a constant low backache, a change in discharge or your water breaking (March of Dimes).
• Later in pregnancy: your baby moving less: Cleveland Clinic lists a significant decrease in your baby’s movements as a reason to seek care right away.
• Heavy bleeding, or your water breaks: Cleveland Clinic says to seek care right away for heavy bleeding, and to call even if your water breaks without contractions. See signs of leaking amniotic fluid.

Go to the emergency room or call 911 if you faint, become confused, cannot keep any fluids down and feel very weak, have severe belly pain that does not ease, or have heavy bleeding and cannot reach your provider quickly. NIDDK lists a change in mental state, such as confusion or lack of energy, among the signs that need a doctor right away.

This article is general education, not medical advice. Your own provider’s instructions come first.

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