The phenomenon known as “period poops” refers to noticeable changes in bowel movements occurring just before or during menstruation, including increased frequency, urgency, or diarrhea. This is a common physiological response to the cyclical hormonal shifts that govern the menstrual cycle. This article explains the specific biological mechanisms responsible for these digestive shifts.
The Primary Culprit Prostaglandins
The principal cause of period-related digestive changes is the production of prostaglandins, a group of lipid compounds. These hormone-like substances are produced by the uterine lining just before and during menstruation. Their primary function is to trigger the smooth muscle of the uterus to contract, which sheds the uterine lining and results in menstrual flow.
The uterus and the intestines are anatomically close neighbors, and their smooth muscle tissues respond similarly to these compounds. When the body produces excess prostaglandins for uterine contractions, these chemicals can travel into the adjacent abdominal area. This causes the smooth muscle in the intestines and colon to contract, speeding up the movement of waste through the digestive tract. This increased motility leads directly to more frequent bowel movements and often results in looser stools or diarrhea.
Other Hormonal Shifts and Timing
While prostaglandins are the direct trigger for diarrhea, the overall digestive experience is shaped by other hormonal fluctuations. During the luteal phase (the second half of the menstrual cycle), the hormone progesterone is elevated. Progesterone has a muscle-relaxing effect on the digestive tract, slowing gut motility and often leading to sluggish digestion and constipation before menstruation.
As the period begins, progesterone levels sharply drop, effectively removing the “brakes” from the digestive system. This sudden withdrawal, combined with the simultaneous rise of prostaglandins, causes the rapid change from premenstrual constipation to menstrual diarrhea. These digestive symptoms are typically confined to the first one to three days of bleeding, when prostaglandin production is at its peak.
Practical Tips for Relief
Managing the discomfort associated with period-related digestive changes involves simple lifestyle adjustments. Staying well-hydrated is important to replace fluids lost due to diarrhea or to help soften stools if constipation is present. For diarrhea, increasing soluble fiber from foods like bananas and oats can help bulk up the stool. Conversely, increasing insoluble fiber from leafy greens can help stimulate movement if constipation is the problem.
Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, offer an effective pharmacological option. These medications work by inhibiting prostaglandin production. To maximize effectiveness against both cramps and digestive symptoms, take NSAIDs prophylactically, starting a day or two before the expected onset of the period.