Hormones (Estrogen and Progesterone), Bloating & Digestion Issues

While we may not think of sex hormones as being involved in digestion, cells in the lining of the intestine respond to the presence of estrogen and progesterone. This means that estrogen and progesterone send cellular messages to the intestine and influence how your gut works. 

Estrogen stimulates the muscle that lines the length of the intestine, working to move food quickly through the digestive tract with specialized muscle contractions known as peristalsis. Progesterone, on the other hand, has a more relaxing effect and slows the amount of time that food spends passing through your intestines. This creates a natural equilibrium that is unique to each individual. Fluctuations of these hormones can trigger constipation or diarrhea depending on whether it speeds up or slows down the action of peristalsis.

During the menopausal transition, our hormone levels start to vary considerably, and this natural digestive balance gets disturbed. When progesterone levels increase relative to estrogen levels you can get constipated. On the other hand, when estrogen levels increase compared to progesterone levels you can end up with diarrhea. The fluctuations in both progesterone and estrogen – individually and relative to each other – are also the root cause of other uncomfortable feelings of indigestion, bloating, gas, and nausea. [3] [4][5] 

Estrogen and Pregnancy Hormone hCG

Some women approaching the menopausal transition report feelings of morning sickness, similar to what they experienced during pregnancy. The exact cause of ‘menopause morning sickness’ is not clearly understood, but it is likely caused by changing hormone levels, particularly human chorionic gonadotropin (hCG) levels. HCG is a hormone produced by the placenta and hCG levels are normally measured to diagnose and monitor pregnancy. However, hCG levels can also be elevated as a result of some serious health issues including cancers. [6]

A recent study showed that elevated hCG levels have been detected in as many as 0.2% to 10.6% of perimenopausal and postmenopausal women who are not pregnant and have no disease or tumor. If you are experiencing menopausal morning sickness, you may want to ask your healthcare provider to have  your hCG levels checked. If nothing else, it can rule out a menopausal transition pregnancy! If you experienced morning sickness during any pregnancy, you are more likely to experience nausea during the menopausal transition. [6]

Cortisol – The Stress Hormone

If you are experiencing abdominal issues during the menopausal transition, you may want to check your stress levels because stress is known to directly affect your gut. In some cases, hormones can cause your body to think it’s stressed, so you get stomach troubles even though you are not actually under any observable stress. [3]

Cortisol is the stress hormone and it gets activated during times of threat where it is a key factor in your fight, flight or freeze response. When cortisol levels increase, it raises blood pressure and adrenaline levels. Together, these switch off digestive functioning and reduce the production of essential stomach acids. The result is indigestion and an upset stomach.[3]

Declining estrogen levels can cause circulating cortisol levels to increase. As well, changing levels of follicle-stimulating hormone (FSH) and testosterone are all associated with significant increases in overnight cortisol levels and this is known to disrupt your regular sleep cycles causing fragmented sleep, insomnia and potentially shortening the overall amount of time you spend asleep. [7] [7a]

The Gut’s Microbiome

Our guts contain what is known as a microbiome, which is the unique collection of microorganisms, including fungi and bacteria, that live inside each of us. The microbiome in our gut is important because it helps regulate our body’s overall metabolism, defined as the conversion of food into chemical energy that is then used to power the body’s activities and to build all parts of the body’s structure, including bones, muscle and fat. Additionally, the microbiome impacts the rate at which estrogen is broken down into its different components, so changes in the gut microbiome can impact the levels of circulating estrogens. [8]

The significant hormone fluctuations during the menopausal transition can alter the gut microbiome and this in turn can affect your hormones, although the exact mechanism driving this cycle between the microbiome changes and hormonal changes is an area of active research. Regardless of why your microbiome changes, when it does it will almost certainly impact your abdominal health and you may experience many abdominal issues including bloating, constipation, diarrhea, gas, and cramping.  [5][9]

Endometriosis

Endometriosis is an estrogen-dependent inflammatory disease. It can cause severe pain – sharp, stabbing, gnawing, or throbbing in your abdomen and occasionally in your back (your ovaries and uterus are located near your lower-mid back). The pain may also be felt in your legs because endometriosis can impact the nerves that attach in your groin, hips and legs, so you could have difficulty walking if you are experiencing a flare-up. [9a] Endometriosis happens when the tissue that is normally found inside your uterus, called endometrial tissue, starts to grow on the outside of the uterus. 

Approximately 2 to 10 % of US women have been diagnosed with this condition based on the common symptoms of pelvic and intestinal pain. Other symptoms of endometriosis include very long or heavy periods, severe cramps, severe migraines during your period (while the link is poorly understood, migraines are associated with endometriosis), pain when you urinate or defecate, allergies that get worse around your period, vaginal bleeding between periods, blood in your urine or from your rectum, fatigue, nausea, diarrhea or constipation and bloating. Women may also experience trouble getting pregnant. [9a]

Treatment for endometriosis can start after the condition is confirmed based on a pelvic exam, ultrasound, magnetic resonance imaging (MRI – a type of scan that creates detailed images of your organs and tissues) or laparoscopy, which is a surgical procedure that uses a laparoscope inserted into your abdomen to look directly at the uterus to see if there is endometrial tissue present. Research on endometriosis “biomarkers” is underway to try to develop low-cost, non-invasive, medically-certified tests for patients with symptoms of endometriosis. [9c] 

Endometriosis Treatment usually involves either medication or surgery. Medications include pain relief and/or hormone therapy (HT), which can slow the growth of the endometrial tissue and prevent new growth from happening. Your health care provider will work with you to determine if HT is a good option and if so, which type will be most effective for your body. Surgery is usually reserved as an option for women who are trying to conceive. [9b]

Until recently, endometriosis was thought to be a condition only found in younger women, most of whom could be expected to experience relief when they entered menopause due to the drop in estrogen levels following the menopausal transition. It is possible, however, for women in the menopausal transition or fully in menopause to experience endometriosis, even if they do not have a history of it. 

This is considered to be very rare, however, and diagnosis is difficult because of a lack of easy diagnostic tests. A diagnosis of endometriosis, whether pre or post menopause, usually happens when all other causes have been ruled out. If you believe you are experiencing symptoms of endometriosis you may have to strongly advocate to receive a diagnosis and treatment. Because many of the symptoms overlap with other possible problems, it can be challenging for women to get the diagnostics necessary to confirm the condition. [10]

Cortisol & Stress

Abdominal problems are widely accepted as one of the consequences of increased stress levels. Cortisol is known as the stress hormone because it is closely linked to the fight, flight, or freeze response that humans typically experience in response to a threat. The most common cause of increased cortisol levels in women is a high circulating concentration of estrogen that causes an increased concentration of cortisol-binding globulin (CBG) in the blood. CBG is the molecule that carries cortisol around in the blood so it can be delivered to target organs and tissues throughout your body – when there is more CBG circulating, there is more cortisol circulating, potentially increasing levels of stress responses in the body. [11] [11a]

In general, stressful situations are known to decrease gastrointestinal motility often resulting in constipation. One study compared premenopausal, perimenopausal, and postmenopausal women under stress situations to assess how changing hormone levels, particularly estrogen, affected movement through the gut. The hypothesis was that perimenopausal and postmenopausal women would experience less of a stress response (i.e. their gastrointestinal motility would not slow as much) as premenopausal women because the premenopausal women have higher levels of estrogen. Surprisingly, the study demonstrated that premenopausal and postmenopausal women showed the expected decrease in gastric motility in response to stress. The perimenopausal group, however, did not demonstrate a decrease in gastric motility under stress. [12] 

This was a pilot study, meaning that it was a small study (in this case there were 55 women involved) to test research protocols and techniques in preparation for a larger study. The unexpected results means that further research is now underway to try and explain why postmenopausal women (who were not expected to show a stress response) did in fact, have the same response as premenopausal women, despite having very different levels of estrogen circulating through their bodies. What the researchers did conclude (beyond the need for further study) is that abdominal issues are affected by decreased estrogen levels, but these issues can resolve over time even without estrogen supplementation. In other words, there is hope that your problems will get better on their own. [12]

Gut Microbiome

There are trillions of bacteria, fungi, viruses and other microbes living in your body and making up your microbiome. Menopause has been shown to alter the gut microbiome and decrease the diversity of microbes living there. [9] Up to 1,000 species of bacteria are typically found in the human gut microbiome, particularly in the large intestine. 

The gut microbiome is very important to your health by helping to digest certain foods and control the immune system. [13] There is growing interest in understanding the relationship between the complexity and diversity of the microorganisms that inhabit our gut and our corresponding health. Research results are showing that changes to the microbiome can lead to many physiological and behavioural problems including changes to the activity of neurotransmitter systems and to immune system functions. [14] 

The gut microbiome has been shown to be influenced by estrogen, however, the gut microbiome also significantly impacts estrogen levels through the secretion of β-glucuronidase, an enzyme which breaks down estrogen and allows it to bind to estrogen receptors. [8] [13][14]  

Abdominal Cancers

Estrogen is suggested to play a protective role in gastrointestinal cancers, with men showing much higher incidences than premenopausal women. While men may have higher incidences, women do get gastrointestinal cancers, and colorectal cancer is the second most commonly diagnosed cancer in females. Obesity, diet, and smoking are the highest risk factors for colorectal cancer. [14]

The hypothesis that estrogen plays a protective role for colorectal cancers is supported across different types of abdominal cancers and across multiple different studies. For example, a global assessment of over 100,000 cases of esophageal adenocarcinoma found that almost 80% occurred in men. In addition, other studies showed that hormone therapy in postmenopausal women significantly decreased the risk of this type of cancer and have also shown as much as a 50% decrease in gastric cancer experienced by women on hormone therapy compared to women with either a placebo or no therapy. [14]