Diarrhea is defined as having three or more loose or watery bowel movements within a 24-hour period. It is a common experience during the third trimester of pregnancy. This digestive change often causes concern because it shifts from the typical constipation many experience earlier in pregnancy. Understanding the reasons behind this change can help manage the symptom and alleviate worry. Maintaining health and hydration is paramount as the body nears delivery.
Physiological Reasons for Digestive Changes
The digestive system reacts to hormonal and mechanical factors specific to the last months of pregnancy. A major contributor is the continuing surge in pregnancy hormones, which alters the balance and activity of the gut, sometimes leading to increased bowel movements. New sensitivities to foods that were previously tolerated are also common, as the body’s physiological state changes. These sensitivities can trigger gastrointestinal upset and loose stools.
The growing uterus exerts significant pressure on surrounding organs, including the intestines. This mechanical compression can affect the normal transit time of waste, sometimes accelerating it and resulting in diarrhea. Furthermore, adjustments in dietary supplements, such as increased iron or magnesium, can disrupt the digestive process. While iron supplements often cause constipation, they can also lead to unpredictable bowel changes in some individuals.
Diarrhea as a Potential Sign of Approaching Labor
A specific cause of third-trimester diarrhea is the body’s natural preparation for labor. This digestive “cleansing” effect is linked directly to the release of hormones called prostaglandins. Prostaglandins are released to help ripen and soften the cervix in preparation for delivery. They also have a stimulating effect on the smooth muscles of the digestive tract.
This hormonal action causes the intestines to contract, often resulting in loose stools or diarrhea. The release of prostaglandins indicates that the body is beginning the cascade of events leading to birth. This can occur in the final 24 to 48 hours before labor starts, but it is not a precise timeline. It may happen a week or two before the onset of contractions. Therefore, diarrhea alone does not confirm that labor is imminent.
Immediate Steps for Symptom Management and Hydration
The most important step when experiencing diarrhea is to prevent dehydration, which can become serious during pregnancy. Lost fluids and electrolytes, such as sodium and potassium, must be quickly replaced to maintain the body’s balance. Drinking plenty of water is fundamental. Supplementing with oral rehydration solutions, sports drinks, or clear broths can help replenish lost minerals.
In the short term, dietary adjustments can help rest the digestive system and firm up stools. A bland diet, often referred to by the acronym BRAT, is recommended: Bananas, Rice, Applesauce, and Toast. Temporarily avoiding greasy, spicy, or high-fiber foods will prevent further irritation of the intestinal lining. Limiting or avoiding dairy products is also wise, as diarrhea can cause temporary lactose intolerance.
Warning Signs That Require Immediate Medical Attention
While mild, short-lived diarrhea is common, certain accompanying symptoms necessitate an immediate call to a healthcare provider. The presence of blood or mucus in the stool may indicate a serious infection or inflammatory process and is a major concern. Likewise, any persistent fever above 100.4 degrees Fahrenheit suggests a bacterial or viral infection that requires medical assessment and treatment.
Signs of severe dehydration, such as dark-colored urine, extreme dizziness, a dry mouth, or reduced urination frequency, require immediate attention. If the diarrhea is accompanied by intense, rhythmic abdominal cramping or contractions, especially if occurring before 37 weeks of gestation, it could signal preterm labor. A healthcare provider needs to evaluate these symptoms to determine the cause and ensure the well-being of both the mother and the fetus.