Frequent hormonal changes that occur in pregnancy, along with a woman's body preparing to push a baby out, lead to diarrhea during preterm labor, explains BabyMed. Loose bowel movements prepare a woman's body for the stages of childbirth through the loosening of the rectum, uterus and other muscles that regulate a bowel movement, notes What to Expect. The emptying of a woman's bowels ensures that there is enough room for baby to pass through the birth canal.
Due to the decelerated digestive process, many women experience constipation during pregnancy, states BabyMed. This can change at a any time, and it often does toward the end of pregnancy. While continuous loose bowel movements may be frustrating, it does not necessarily indicate labor. If cramping or contractions accompany the diarrhea, the beginning stages of labor may be evident. Many women experience diarrhea during active labor as well.
When dealing with diarrhea during pregnancy, it is important to stay hydrated with water, advises What to Expect. Other things that are helpful include eating a piece of toast with jelly, a cup of broth or a fruit pop. It is critical to avoid fatty foods, such as fried foods, dairy products and meat; anything filled with fiber, such as bran muffins; and anything acidic, including orange juice.