Is The Runs A Sign Of Labour?

Diarrhea in late pregnancy is common, and for many women, it is one of the first signs that labour is approaching. While it is not a guarantee that labour has started, loose stools are a recognized early indicator that your body is preparing for birth. This happens because of hormonal shifts that relax your muscles and empty your bowels in the days or hours before contractions begin.

Why Does Diarrhea Happen Before Labour?

Your body goes through specific changes in the final weeks of pregnancy. One of the most significant is a rise in prostaglandins. These hormone-like substances help soften and thin the cervix, a process called effacement. They also affect the smooth muscle in your intestines.

Prostaglandins stimulate the bowel to contract and empty. This is a natural and purposeful process. It clears the lower bowel to make more room for the baby to descend into the birth canal. It also reduces the chance of stool being passed during active pushing in the second stage of labour.

This is the same mechanism behind the “nesting instinct” and the sudden urge to clean the house. Your body is making final preparations, and that includes emptying the digestive tract.

When Does Loose Stools Typically Start?

For many women, diarrhea begins 24 to 48 hours before labour starts. However, this timeline is not fixed. Some women notice loose stools several days before their due date, while others experience it only hours before contractions begin. Some women have no diarrhea at all before labour.

It is important to understand that diarrhea alone does not mean you are in active labour. It is a preparatory sign, not a definitive one. Active labour is confirmed by regular, progressive contractions that cause cervical change. Diarrhea is one piece of the puzzle, not the whole picture.

If you have loose stools but no contractions, it may simply be a sign that labour is approaching in the coming days. If you have diarrhea alongside regular contractions that are getting stronger and closer together, labour is likely underway.

Other Signs That Labour Is Near

Diarrhea rarely happens in isolation. It usually occurs alongside other pre-labour signs. Recognizing these together can give you a clearer picture of where you are in the process.

• Loss of the mucus plug: A thick plug of mucus that sealed the cervix may come away as a jelly-like discharge. This can happen days before labour or during labour itself.
• Bloody show: A small amount of blood mixed with mucus often accompanies the loss of the mucus plug. This is a normal sign of cervical changes.
• Water breaking: A gush or steady trickle of amniotic fluid means the membranes have ruptured. If your water breaks, contact your maternity team regardless of whether contractions have started.
• Regular contractions: Contractions that come at consistent intervals, last longer, and grow stronger are the most reliable sign of active labour.
• Lower back pain and cramping: Many women feel a dull ache in the lower back or period-like cramps that come and go.

If you have several of these signs along with diarrhea, labour is likely close. If you only have diarrhea, it is less certain but still a reasonable indicator that your body is gearing up.

Is It the Runs or Something Else?

Not all diarrhea in late pregnancy is related to labour. Food poisoning, stomach bugs, and food sensitivities can all cause loose stools. The key difference is usually in the other symptoms you experience.

Labour-related diarrhea is typically mild and short-lived. It is not accompanied by vomiting, fever, or severe abdominal pain. A stomach bug or foodborne illness often causes nausea, vomiting, fever, and cramping that is more intense than typical pre-labour discomfort.

If you have diarrhea with a fever above 100.4°F (38°C), vomiting that prevents you from keeping fluids down, or severe pain that does not ease, contact your healthcare provider. These symptoms suggest an infection rather than normal pre-labour changes.

Dehydration is a real risk with diarrhea, especially in late pregnancy. Make sure you are drinking water, clear broths, or an oral rehydration solution. If you cannot keep fluids down for more than a few hours, seek medical advice.

What Should You Do If You Have Diarrhea at 39 or 40 Weeks?

If you are full-term and experiencing loose stools, the first thing to do is stay hydrated. Diarrhea can quickly deplete your fluids, and dehydration can complicate labour. Sip water frequently and eat bland, easy-to-digest foods like toast, crackers, bananas, and rice if you feel like eating.

Do not take anti-diarrheal medication without speaking to your healthcare provider first. Many over-the-counter options are not recommended during pregnancy. Your body is doing something purposeful, and stopping that process is not usually advised at this stage.

Pack your hospital bag if you have not already. Note the time of your last bowel movement and whether you have any other signs of labour. If you start having regular contractions, time them from the beginning of one to the beginning of the next.

Call your maternity unit if your water breaks, if contractions are five minutes apart lasting about a minute each for an hour, or if you have any concerns about reduced fetal movement. They will advise you on the next steps based on your specific situation.

What If Diarrhea Happens Earlier in Pregnancy?

Diarrhea in the second or early third trimester is less likely to be related to labour. At that stage, it is more commonly caused by a stomach bug, food intolerance, or a change in your prenatal vitamins. Some women find that iron supplements cause loose stools or constipation, depending on the formulation.

If you are not near your due date and have diarrhea lasting more than a couple of days, or if it is accompanied by signs of dehydration, contact your healthcare provider. Persistent diarrhea can affect your nutrient and fluid balance, which matters for your baby’s growth and your own health.

Severe or bloody diarrhea at any stage of pregnancy warrants prompt medical attention. This is not a sign to wait out at home. Call your doctor or midwife immediately.

Can Diarrhea Cause Early Labour?

There is no evidence that diarrhea itself triggers early labour. The hormonal changes that cause diarrhea are the same ones that help prepare the cervix, but the diarrhea is a side effect, not a cause. A mild stomach upset that causes loose stools will not induce labour.

Severe dehydration from prolonged diarrhea, however, can cause problems. Dehydration can lead to reduced amniotic fluid and may trigger contractions. This is why staying hydrated is so important, especially in the final weeks.

If you are preterm and experiencing diarrhea along with cramping, back pain, or pelvic pressure, contact your healthcare provider. These symptoms together could indicate preterm labour, and you should be assessed promptly.