Diarrhea During Pregnancy – From Day One through Labor

Diarrhea while you’re pregnant is a somewhat common occurrence although it can occur at different stages and some women won’t experience it at all. It tends to be more uncomfortable or annoying than anything else, and is usually nothing to worry about. If the problem becomes chronic or severe however, it can become a serious situation, possibly leading to dehydration in the mother and potentially becoming a danger to the fetus or unborn baby. It is important to recognize however, that while it can be one of the signs leading to a miscarriage, in itself, it is not a sign that a miscarriage is about to occur.

As a general rule of thumb, if the problem persists for more than three or four days and if it is accompanied by vomiting, cramping, or is black or green in color it can be a sign of a potentially serious disorder and it will be wise to seek medical advice and attention.

Diarrhea as a Sign of Pregnancy

Unfortunately for many, diarrhea and pregnancy often go hand in hand. In some cases, it is one of the first signs that you may be pregnant, even before you realize you’ve entered the first trimester. The signs and symptoms that accompany this earliest stage of pregnancy are not always that comfortable. While the problem at this point in time is not all that common, it is common enough although more typical signs are changes in smell and appetite, sore or swollen breasts, and stomach upset. The latter may or may not be accompanied by diarrhea but is often accompanied by nausea, gas, or bloating.

When diarrhea does occur at this very early stage, it is usually a result of hormones that are released following conception.

Diarrhea can sometimes occur in the days following ovulation, usually peaking around the 10th day, whether a woman has become pregnant or not, so it is not all that reliable a sign that pregnancy has occurred. Statistics have been compiled on the subject, charting the percentages of women who experience diarrhea following ovulation who have become pregnant as well as for those who have not. Women who have become pregnant are about three times more likely to experience diarrhea over a 21 day period than those who are not pregnant. At the peak, about 3.5 percent of women who have become pregnant experience diarrhea on the 9th or 10th day following ovulation compared to 0.75% of women who have the same experience on the 9th or 10th day but are not pregnant. The percentage of those experiencing bouts of diarrhea drops off sharply in both cases after the 10th day.

Early Pregnancy

As is the case during the first several days of pregnancy, diarrhea that is occurring during the first trimester tends to be due to a combination of changes in hormones and changes in diet. These are both changes that the digestive system can sometimes have difficulty adjusting to and when they occur simultaneously, it is even harder for the digestive system to adjust. Consequently, having symptoms in the first trimester are not all that uncommon. During this period, a woman is also more susceptible to viral infections which can increase the chances of stools becoming overly loose or watery.

In most instances where diarrhea is occurring during the first trimester, it is more apt to be the result of   food that is being eaten or due to a bacterial or viral infection than with the pregnancy itself. The same is true for the second trimester of a pregnancy.

Late Pregnancy

Diarrhea during the third trimester is a bit more common than in the earlier two trimesters, but is still not all that common. This is in large part due to an excessive amount of iron that is present in certain prescribed dietary supplements. Women who are pregnant do need additional iron, but it can sometimes be difficult to define just when additional becomes excessive. It is, of course, better to have an adequate supply of iron even if it means putting up with certain discomforts.

Two things worth knowing about diarrhea during the latter stage of pregnancy is that it tends to become more commonplace shortly before going into labor and at times is one of the signs of an impending premature birth. Diarrhea in the third trimester can normally be controlled or avoided by diet modifications that include fiber-rich foods that help bind the stool and foods that encourage re-hydration.

Prostaglandins and Labor

Diarrhea is one of the five major signs that you are going into labor. A late-pregnancy bout of diarrhea doesn’t always mean that is the case and not all women experience the problem prior to going into labor or during labor. If you are in labor, you obviously have other more important things to worry about than runny stools.

As is the case in the earliest stage of pregnancy, changes in your body chemistry can be the reason. Shortly following conception and for several weeks thereafter, hormone changes are a primary cause of diarrhea. During labor, the culprits are hormone-like substances called prostaglandins. Prostaglandins consist of a group of lipid compounds that can produce strong physiological effects. During labor, they regulate the contraction and relaxation of smooth muscle tissues (in this case, the muscle tissues of the uterus.) There are a number of different types of prostaglandins and one reason they are similar but not identical to hormones is that they are produced throughout the body where they perform a number of useful functions.

Prostaglandins, therefore, serve to stimulate contractions and relaxation in the uterus, setting the stage for delivery. On the other hand, there are instances where these same compounds will have a similar effect on the smooth muscles lining the intestines, causing those muscles to relax and/or contract. If the muscles in your colon or rectum become hyper stimulated and relaxed at inappropriate times, there can be a discharge of liquids or stools. This does not happen in all cases, and in fact, occurs in a minority of cases, but if you experience a bout of diarrhea while in labor, it is most likely a result of prostaglandins doing more than they should be doing at the time.


There are basically two things you can do to avoid having problems with diarrhea during pregnancy. You can take medication designed to prevent occurrences and you can make certain changes in your eating habits.

  • Medications – There are many over-the-counter anti-diarrhea medications that are safe to use while you are pregnant, although it is always wise to first check with your doctor or obstetrician to make sure the medication you are considering taking will not do harm to your unborn baby or yourself. Products that contain bismuth should be avoided as they generally contain salicylates, compounds that should be avoided while pregnant.
  • Diet – As far as diet is concerned, avoiding foods that contain natural laxatives, such as prunes and other dried fruits can be helpful. Spicy and fatty foods can also create conditions that at times can lead to a bout of diarrhea, primarily because these types of foods are sometimes difficult for the body to assimilate. Sugary foods, especially beverages that have high sugar content can also lead to problems and should be avoided or taken in moderation. Foods high in sugar will not necessarily cause diarrhea, but can make it more severe and long-lasting if it should occur. As a rule of thumb, foods that may cause weight gain also tend to lead to conditions that can cause bowel movement problems. Almost any diet that would be considered to be a healthy diet will probably help keep your bowels from acting up as well. If you are looking for a specific diet because you have concerns about diarrhea, you might consider a diet based on bananas, toast, applesauce and rice. It’s called a BRAT diet and also includes lean meats, carrots, light soups, yogurt, potatoes, and enriched cereals.
  • Food Intolerance and Supplements – If you are lactose intolerant, you may want to avoid dairy products if you do not already do so as lactose can sometimes contribute to digestive problems. Foods that are especially good for you on the other hand are those that contain zinc. Most diets are somewhat deficient in zinc and an adequate intake of this mineral is particularly important during pregnancy. If necessary, your doctor or obstetrician may recommend supplements containing zinc or other vitamins or minerals.
  • Hydration – Don’t forget to drink plenty of water to keep hydrated. Drink juices and broth as well to replenish electrolytes you may have lost. Dehydration is usually the main danger associated with this bowel disorder, but it will seldom become a problem if you make it a point to take in plenty of liquids each and every day.
  • Avoiding Traveler’s Diarrhea – A final point is worth mentioning. If you have done much traveling, you are probably familiar with what is known as traveler’s diarrhea, whether you have actually experienced it or not. This condition is usually brought about by unclean food, particularly food that may be consumed in an area where sanitation is poor. Drinking water is also a main source of this particular disorder. More and more people rely on bottled water when away from home, and especially when traveling in certain foreign countries. Traveler’s diarrhea is something everyone would like to avoid, but it is especially important to attempt to avoid it if you happen to be pregnant.

In summary, diarrhea can strike at any time during a pregnancy, from day one up until and including going into labor. If it occurs within the first few days or weeks of pregnancy, hormonal changes would be the most likely cause. During the first trimester and into the second trimester, any problems you might have will usually be due to bacteria or a virus. In the third trimester, diet can become a factor and the probability tends to increase not long before going into labor. In this case, it is hormone-like substances called prostaglandins that are usually the source of the problem. Diarrhea during pregnancy is seldom a serious problem, but can be if you allow yourself to become dehydrated. In any event, if you are experiencing repeated bouts of the problem in a short period of time, you should see your doctor.