One common complaint that many women experience around their cycle is gastrointestinal distress. The prevalence of digestive issues before and during their menstrual cycle has been reported to occur in one-third of healthy women.

This article will explore how the menstrual cycle affects the gut and offer some tips for managing these symptoms.

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6 Ways Our Menstrual Cycles Affect Our Bowel Movements

Hormones are powerful chemical messengers that have a wide range of effects on many different biological processes. Since their receptors are found throughout the whole body, hormonal fluctuations during one's menstrual cycle can result in various premenstrual syndrome (PMS) symptoms. These include mood swings, cramps, and digestive issues. (1-5)

Before and during the menstrual cycle, women often experience gastrointestinal discomfort, constipation, diarrhea, and alterations in the frequency of bowel movements. These changes have been referred to as "period poop." (3-7)

The gastrointestinal shifts during a women's cycle occur for several reasons. They can differ in severity based on a woman's overall health and underlying reproductive and gastrointestinal conditions. (3-7)

Prostaglandins Signal Uterine and Gut Muscle Contractions

Prostaglandins are a class of compounds, eicosanoids, derived from polyunsaturated fatty acids. They have diverse roles in the body that include modulating inflammation, stimulating muscle contractions in the gut and uterus, and repairing tissue damage. They are also important regulators of various reproductive processes, including ovulation (the release of an egg from the ovary), fertilization, and pregnancy. During your period, more prostaglandins are released to help shed the uterine lining. (9-13)

The stimulation of movement in the gastrointestinal (GI) tract signaled by prostaglandins can lead to increased bowel movements, diarrhea, softer stools, and menstrual cramping. This can amplify discomfort in the gut and reproductive organs and alter bowel frequency. (9-13)

Sex Hormones Influence on the Gut

Sex hormones influence the gastrointestinal (GI) tract by regulating motor, sensory, and immune function. This is through their interaction with neurotransmitters that bidirectionally signal information from the gut to the brain. As a result, the fluctuations in levels of hormones before and during the period can contribute to alterations in pain sensitivity, motility, gut permeability, local and systemic inflammation, and immune imbalances. This can lead to a worsening of bowel symptoms and uterine discomfort. Emotional symptoms can also occur in conjunction with GI symptoms via the gut-brain axis. These can exacerbate distress.

As hormones rise and fall, changes in stool consistency and frequency can be predicted. In healthy women, stools are often looser and more frequent with their period but firmer during the luteal phase (post ovulation to the day one's menstrual cycle). During the luteal phase, delayed gastrointestinal transit and constipation can also ensue. (1-8, 15-16)

Hormonal Aggravations of GI Conditions

Irritable Bowel Syndrome (IBS)

Whereas one-third of women with no gastrointestinal diagnosis experience symptoms during menstruation, about 40% of women with IBS report that menstruation affects their symptoms.

Women with functional bowel disorders (FBDs), such as IBS, likely respond differently to the fluctuations in ovarian hormones. (14-16) This may be related to motor disturbances or perceptual alterations in GI contractions and the changes in the alterations in gut mucosal (the lining of the GI tract) immunity. For example, in one study with 29 IBS females, menses were associated with worsening abdominal pain and bloating, more frequent bowel habits, increased rectal sensitivity, and lower general well-being.

The role of sex hormones in IBS supported by the fact that more women suffer from it than men, and females on hormone replacement therapy (HRT) report less frequent bloating than those, not on HRT.

Irritable Bowel Disease (IBD)

Females with inflammatory bowel disease (IBD), such as ulcerative colitis or Crohn's disease, can also experience more gut symptoms during menstruation. They also experience more menstrual-related symptoms in general, such as headaches or menstrual pain. This is likely due to alterations in gut immunity and the impact of the sex hormone prostaglandin signaling on the gastrointestinal system and immune response.

Hormonal Symptoms Aggravating Gut Issues

Endometriosis

Endometriosis is a painful condition in which the tissues lining the uterus grows outside of it. Symptoms of endometriosis include bleeding disorders, painful periods and intercourse, cramping, and gastrointestinal issues. Due to the strong associations between painful periods, gastrointestinal symptoms, and inflammation, endometriosis can often be confused with IBS.  

Inside the uterus, this tissue builds and sheds each month during the menstrual period. But in endometriosis patients, the endometrial-like tissue also builds up and sheds, but it does not have a way to exit the body. This can cause pain, spasms, and gastrointestinal disturbances.

Endometriosis can cause abdominal bloating for other reasons, including:  

• Endometrial tissue builds up and causes the abdomen to become inflamed.
• Endometriosis can lead to digestive issues such as gas and constipation.
  

Cravings and Dietary Shifts

The brain has receptors for estrogen, which suppresses hunger by lowering ghrelin levels and stimulating cholecystokinin, an appetite-suppressing hormone.

When estrogen drops and progesterone peaks about one week before menstruation begins, hunger increases, and cravings kick in. As a result, a shift in diet occurs, which can impact the microbiome. This can result in differences in the consistency, regularity, or smell of the stool before or during one's period.

Stress and Stomach-Related Menstrual Disorders

Stress has been shown to alter GI motility, increase visceral sensation, change intestinal secretions, increase gut permeability, negatively affect gastrointestinal blood flow, and affect the microbiota. Stress induced by PMS or PMDD can modify the communication between the gut and the brain and decrease the "rest and digest" branch of the autonomic nervous system, hindering the digestive process and creating discomfort in the GI tract.

Functional Medicine Lab Test to Help With Proper Diagnosis & Treatment

Conventional labs and imaging should complement functional measurements to assess and rule out possible pathologies in the gut and reproductive organs.

Comprehensive Stool Test

Comprehensive stool tests offer a complete look at gut health by measuring pathogens and analyzing digestion, nutrient absorption, inflammation, and immune function, all of which impact digestive function and symptoms.

Neurotransmitter Test

Due to communication between the gut, hormones, and neurotransmitters, a practitioner may choose to test for levels of these chemical messengers and correlate levels to hormones.

Comprehensive Hormonal Panels

Obtaining a baseline measurement of sex hormones and adrenal function can help address how one's hormonal fluctuations impact digestive changes. These tests can be used to personalize nutritional and hormonal supplemental support throughout the different menstrual cycle phases.

Each type of hormonal test, blood, salvia, and urine, has been touted to have unique advantages and disadvantages, and they are often chosen based on practitioner preference.

How To Ease Menstrual Cycle-Digestive Symptoms

Nutrition

• A low inflammatory organic whole foods-based diet can help decrease hormone-disrupting chemicals and keep blood sugar and insulin balanced. (22-23). Both are important factors in regulating hormones and reducing overall inflammation.
• Whole foods high in b-vitamins (grains, meats, legumes, etc.) and magnesium (nuts, seeds, chocolate, whole grains) should be incorporated to support neurotransmitter production and calm the gut-brain axis.
• Fermented foods, foods high in polyphenols (cocoa, green tea, etc.), and fiber-rich foods can all feed the gut microbiome and support healthy digestive function, which can help ease digestive symptoms.
• Increasing specific types of fiber-based on symptoms can also help to ease digestive discomfort and support a healthy microbiome.
• For those suffering from slower bowels or constipation during the luteal phase, increasing insoluble fiber may help. Insoluble fiber can help relieve constipation by speeding up the transit of food in the digestive tract.
• For those suffering from looser stools during the menstruation phase, soluble fiber can help. Soluble fiber attracts water and becomes gel during the digestive process, slowing the movement and increasing the bowels' firmness.
  

Exercise

Moderate exercise has been shown to positively alter the microbiome and impact the production of beneficial metabolites which support gut health. There is also evidence that exercise improves mood and changes brain neurochemistry for better mental functioning. These effects can support the stress-induced changes and cravings that impact gastrointestinal function within a woman's cycle.

Sleep

Proper amounts of restful sleep have been found to alter the microbiome, improve hormone levels, and support the function and diversity of gut bacteria. It is also essential for overall mental health.

Stress Reduction

Due to the relationship between the gut, brain, and stress, cognitive behavioral therapy, and stress reduction techniques, such as meditation, gut-directed hypnotherapy, and relaxation therapies, can help manage gut discomfort and improve other symptoms. (26-28)

For example, a recent review found that stress management techniques positively affected inflammatory activity, anxiety status, and quality of life in IBD patients.

In another study with 98 college students, five weeks of daily self-practices of awareness of stress response, muscle relaxation, diaphragmatic breathing, and posture awareness, a 73% reduction in anxiety, 68% reduction in stress, 27% reduction in neck and shoulder discomfort, 26% reduction in abdominal pain; 18% of abdominal discomfort, and 16% reduction in menstrual cramps was reported.

Essential Oils

Aromatherapy, which includes clary sage, lavender, geranium, rose, and neroli, has been shown to help to balance hormones by supporting estrogen levels.

Peppermint oil has been shown in many trials to be useful for digestive-related complaints. Peppermint oil contains L-menthol, which has been shown to block calcium channels in smooth muscle, creating an antispasmodic effect on the gastrointestinal tract. It also possesses antimicrobial, anti-inflammatory, antioxidant, immunomodulating, and anesthetic properties, which can help relax the bowels and reduce pain associated with IBS.

Herbs and Supplements

Herbs can support digestive health due to their interaction with the gut microbiota. The gut microbiota "digests" the herbal medicines into absorbable, active small molecules, which can lead to beneficial biological changes by altering the gut microbiota and its secretions, leading to beneficial physiological changes.

Various herbs are commonly selected for an individual based to relieve symptoms. For example, herbs that help balance estrogen and hormone levels, such as Pueraria Mirifica and phytoestrogens, may be helpful for hormonal shifts. Pueraria Mirifica is a natural selective estrogen receptor modulator (SERM), supporting healthy levels and alleviating symptoms of low estrogen.

Adaptogenic herbs that modulate stress, such as ashwagandha, Schisandra, and Eleutherococcus, have been shown to improve resiliency and reduce fatigue. Which may help modulate the stress-related gut disturbances that can occur with the menstrual cycle.

Herbs specific for reducing PMS symptoms that are safe and effective include:

• Vitex agnus castus, also known as Chasteberry
• ‍Evening Primrose Oil has also been shown to support PMS symptoms, though it may take 4-6 months to get an optimal response.
• ‍Jia Wei Xiao Yao San a Traditional Chinese Herbal formula. This blend of herbs is used for symptoms of PMS and to help relieve cramps, irregular menstrual cycles, and infrequent periods.
  

Probiotics are helpful for various gastrointestinal and functional digestive issues and may help relieve symptoms. One randomized study with 100 patients who experienced slow transit constipation reported that those taking a synbiotic (a combination of prebiotics and probiotics) had a much more significant clinical improvement over those taking the placebo.

Saccharomyces boulardii, a type of fungal probiotic, has been found support a healthy gut lining, enhance SIgA (a marker of intestinal health and immunity), enhance microbial balance, and have evidence for efficacy in treating diarrhea. (36-38)

Magnesium, if low, may also be helpful due to its role in hormonal health, prevention of painful periods, and brain balance. (39-40) Magnesium citrate is commonly used for those suffering from constipation during the luteal phase.

Summary

The hormonal shifts that occur with the menstrual cycle influence the gastrointestinal tract for various reasons. Changes in prostaglandins, sex hormones' interactions with gut and brain neurotransmitters, underlying gut and endocrine issues, stress, craving, and dietary shifts all impact a women's experience of "period poop" during her cycle.

Thankfully, addressing the root cause with lifestyle medicine, stress reduction, mind-body modalities, nutrition, herbs, and supplements can help to bring the hormones and gut back into balance. This will likely alleviate much gut woos that plague women during their cycle.