The causes of diarrhea during the early stages of pregnancy vary, with some women experiencing more severe symptoms than others. Characterized by three or more watery stools within a 24-hour period, diarrhea often dissipates on its own in as little as two days, according to the National Institute of Diabetes and Digestive and Kidney Diseases. First-trimester diarrhea that lingers beyond two days may require medical attention to determine the origin and treat the symptoms.
The surge of hormones that bombard a woman's body during early pregnancy often trigger bouts of nausea known as morning sickness. In her book, “Feed the Belly,” Registered Dietician Frances Largemen-Roth explains that hormones such as HCG, or human chorionic gonadotropin, are responsible for the stomach discomfort. Stomach and gastrointestinal upset often go hand in hand, which is sometimes the case with morning sickness, especially when the rush of HCG hormone produces diarrhea symptoms.
Changes to diet during the early stages of pregnancy may upset the digestive system, resulting in instances of diarrhea that come and go. While diarrhea brought on by dietary changes is often temporary, prolonged cases may result in women who present with sensitivities to certain foods. In fact, some women develop sensitivities to foods tolerated prior to pregnancy, according to the American Pregnancy Association.
Bacterial and viral infections are also responsible for diarrhea symptoms during early pregnancy. Influenza is a common viral infection that causes symptoms such as fever, chills, muscle aches and diarrhea. According to WomensHealth.gov, harmful bacteria, such as listeria, found in improperly handled foods can also lead to serious foodborne illnesses that present with symptoms such as fever, severe headache, nausea and diarrhea in pregnant women.
Diarrhea can quickly lead to dehydration, which is why the American Pregnancy Association recommends that pregnant women drink plenty of water, juice and broth to maintain healthy electrolyte, potassium and sodium levels during these gastrointestinal episodes. Women who experience persistent diarrhea that does not resolve on its own during early pregnancy should seek medical attention to determine the cause. In cases of bacterial infection, antibiotics may be necessary. Medical professionals may also recommend steering clear of certain foods prepared under unsanitary conditions to avoid infection.