The experience commonly referred to as “period poops” describes the changes in bowel habits that occur around the onset of menstruation. These changes often manifest as looser stools, increased frequency of bowel movements, or diarrhea. Studies indicate that a significant percentage of people who menstruate experience some form of gastrointestinal symptom during their cycle. Recognizing this pattern is important because it is a normal response to the body’s natural hormonal shifts, not a sign of underlying digestive illness.
The Role of Prostaglandins
The primary scientific driver behind these digestive changes is a group of lipid compounds called prostaglandins. Prostaglandins are potent, hormone-like chemicals derived from fatty acids that are produced locally throughout the body. Their main function in the reproductive system is to initiate menstruation.
Just before and during the beginning of a menstrual cycle, the cells in the lining of the uterus produce and release high levels of prostaglandins. These compounds bind to receptors on the smooth muscle tissue of the uterus, causing it to contract forcefully. This muscular action is necessary to shed the endometrial lining. The intensity of these uterine contractions determines the severity of menstrual cramps.
When the body produces an excess of these compounds, they can enter the bloodstream. This overflow links the reproductive process to the digestive system. The greater the amount of prostaglandins released, the more pronounced the effects will be on nearby organs.
How the Gut Reacts
The digestive tract, including the intestines and colon, contains the same smooth muscle tissue as the uterus. When excess prostaglandins travel through the bloodstream, they bind to the receptors on these gastrointestinal muscles. The compounds trigger the same involuntary contractions in the bowel as they do in the uterus.
These increased contractions speed up peristalsis, the wave-like movement that pushes waste through the intestines. This accelerated movement means waste passes through the colon faster than usual, resulting in increased frequency of bowel movements or diarrhea. Prostaglandins also increase electrolyte secretion and reduce water absorption in the intestines. These actions contribute to the loose, watery consistency associated with period-related diarrhea.
A secondary hormonal factor contributing to bowel changes is the sharp drop in progesterone levels right before the period begins. Progesterone levels are high during the second half of the cycle, slowing down gut motility and often causing constipation and bloating before menstruation. The subsequent withdrawal of this constipating effect, combined with the spike in prostaglandins, creates the sudden shift from pre-period constipation to period diarrhea.
Finding Relief and Comfort
Managing period-related bowel changes involves proactive steps to mitigate prostaglandin effects and support gut function. One effective strategy is the use of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, taken just before or at the start of the period. NSAIDs inhibit prostaglandin production, reducing both uterine cramping and gastrointestinal distress.
Hydration is important, especially when experiencing diarrhea, which leads to fluid and electrolyte loss. Consuming water and electrolyte-rich beverages helps replenish lost fluids and prevent dehydration. Dietary adjustments can also provide comfort by avoiding known gastrointestinal triggers.
It is helpful to limit gut-stimulating foods, such as excessive caffeine, alcohol, and high-fat or highly processed foods. Focusing on a diet rich in soluble fiber from sources like oats, bananas, and rice can help add bulk to stools and slow down transit time. Tracking symptoms across several cycles can help identify personal triggers, allowing for targeted dietary and lifestyle changes.