1 / Why Has My Digestion Changed After 45?

Perhaps you used to be able to eat almost anything without thinking about it. Now you finish dinner and feel six months pregnant. Foods you have eaten for years suddenly seem to cause bloating. Constipation has appeared from nowhere, reflux has become more frequent, or your bowel habits simply aren't as predictable as they once were.

It is very easy to conclude that your gut has become "damaged" or that menopause has somehow ruined your digestion.

Usually, the picture is more complicated.

Digestion is not one process. It is a coordinated system involving your brain, stomach, pancreas, liver and gallbladder, small intestine, colon, microbiome, nervous system and pelvic floor. A change anywhere along that journey can produce symptoms.

And while ageing and the hormonal transition may influence parts of this system, research into gastrointestinal symptoms specifically during natural peri- and postmenopause is still surprisingly limited.

So rather than blaming every new digestive symptom on estrogen, let's understand what your digestive system is actually doing.

Digestion starts before food reaches your stomach

The moment you see, smell and begin eating food, your nervous system is already preparing your digestive tract.

Chewing mechanically breaks food down and mixes it with saliva. Once food reaches the stomach, gastric acid and enzymes begin the next stage of digestion. The stomach gradually releases its contents into the small intestine, where pancreatic enzymes help break down protein, carbohydrates and fats.

Bile, produced by the liver and stored in the gallbladder, helps emulsify dietary fats so they can be digested and absorbed. The lining of the small intestine then absorbs most nutrients.

What remains eventually reaches the colon, where water and electrolytes are absorbed and trillions of microorganisms interact with material we cannot completely digest ourselves.

Finally, coordinated intestinal contractions move waste toward the rectum, and the pelvic floor and anal sphincters have to work properly for normal evacuation.

So when someone tells me she has "bad digestion," my first question is:

Which part?

Because reflux, bloating, constipation and diarrhoea are not four versions of the same problem.

Your gut has its own nervous system

Your digestive tract contains an extensive network of neurons called the enteric nervous system. It communicates continuously with the brain through neural, hormonal and immune pathways, including communication involving the vagus nerve.

This is part of what we call the gut-brain axis.

It helps explain something most of us have experienced: your emotional state can change what happens in your gut.

Stress can alter intestinal motility and sensitivity. Anxiety can make normal intestinal sensations feel considerably more intense. For some people, stress speeds the bowel up; for others, it appears to slow things down.

This does not mean digestive symptoms are psychological. It means the brain and gastrointestinal tract are biologically connected.

That relationship is particularly important in conditions such as irritable bowel syndrome, where altered gut-brain interaction and visceral sensitivity play important roles.

So if your gut becomes dramatically worse during periods of stress, you are not imagining it. But neither should every digestive problem be dismissed as stress.

Motility matters more than most women realise

Your intestines need to move their contents forward at an appropriate speed.

Too quickly and there may not be sufficient time to absorb water properly, contributing to loose stools or diarrhoea. Too slowly and more water is removed from stool, making it harder and more difficult to pass.

This movement is controlled through interactions between the enteric nervous system, smooth muscle, hormones, the autonomic nervous system, the microbiome, food intake and physical activity.

Medications matter too. Opioid pain medication is an obvious example, but iron supplements, some antidepressants, anticholinergic medications and certain other drugs can contribute to constipation.

Thyroid dysfunction can affect bowel motility as well, which is one reason new constipation accompanied by fatigue, cold intolerance, hair changes or unexplained weight changes deserves a wider look.

And sometimes the problem isn't how quickly stool reaches the end of the colon. It is getting it out.

Constipation isn't always a fibre problem

Constipation is often reduced to "eat more fibre and drink more water."

Sometimes that helps enormously. Sometimes it doesn't.

Constipation can involve infrequent bowel movements, hard stools, excessive straining, incomplete evacuation or the feeling that something is physically blocking the passage of stool. Those distinctions matter.

A woman can have adequate fibre intake and normal colonic transit but struggle because the muscles of the pelvic floor are not coordinating properly during defecation.

This is called a defecatory disorder or pelvic-floor dysfunction, and simply adding increasingly large quantities of fibre may not solve it.

Pelvic-floor changes can become particularly relevant with age and after pregnancy and childbirth.

So if you repeatedly feel that stool reaches the rectum but you cannot evacuate properly, or you have to strain excessively despite relatively soft stool, I don't want you automatically buying stronger laxatives.

I want us to understand where the process is failing.

Bloating does not automatically mean you have too much gas

This is another important distinction.

Bloating describes the sensation of abdominal pressure, fullness or swelling. Distension means there is an observable increase in abdominal size. You can have one without the other.

Gas can certainly contribute. Gut bacteria ferment carbohydrates that reach the colon and produce gases as part of normal metabolism.

But the relationship between gas and bloating is not straightforward. Some people can tolerate considerable intestinal gas with little discomfort, while others experience significant bloating with relatively normal amounts.

Why?

Because bloating can also involve altered intestinal motility, constipation, visceral hypersensitivity and the way the abdominal wall and diaphragm respond to intestinal contents.

This is why the statement "you're bloated because your gut bacteria are producing too much gas" is far too simplistic.

The timing of bloating gives us useful clues. Do you wake with a flat abdomen and become progressively bloated through the day? Does it happen immediately after eating? Only after particular foods? Does it improve after a bowel movement?

Those patterns are more useful than simply deciding you have "dysbiosis."

Reflux is not simply too much stomach acid

Reflux occurs when stomach contents move backwards into the oesophagus.

Stomach acid is certainly involved in the irritation and symptoms, but the underlying problem is not necessarily that your stomach produces excessive acid.

The lower oesophageal sphincter normally helps prevent stomach contents travelling upwards. Transient relaxation of this sphincter, increased abdominal pressure, hiatal hernia, delayed gastric emptying, body weight, certain foods, alcohol and other factors can influence reflux.

This distinction matters because the internet has created another very attractive explanation for midlife women:

"You don't have too much stomach acid. You have too little."

Low stomach acid can occur in particular circumstances, including atrophic gastritis and with acid-suppressing medication. But the idea that stomach acid simply declines dramatically in every healthy person as they age is not well established.

So please don't diagnose yourself with low stomach acid because you have reflux and start taking hydrochloric acid supplements.

Find out what is actually happening first.

Then there is your microbiome

Your gastrointestinal tract contains a vast ecosystem of microorganisms collectively known as the gut microbiome.

These organisms are not simply passengers.

Gut microbes ferment dietary components that our own digestive enzymes cannot completely break down. In doing so, they produce metabolites including short-chain fatty acids, such as acetate, propionate and butyrate.

These metabolites can interact with intestinal cells, immune signalling and metabolism. Butyrate, for example, is an important energy source for cells lining the colon.

The microbiome also interacts with bile acids, medications and numerous compounds produced by our own bodies.

This is why gut microbiome research is so exciting.

It is also why it is so easy to oversell.

There is no single perfect "healthy microbiome" composition that every woman should have. Microbial communities differ considerably between individuals and populations, and menopause research has not identified one ideal menopausal microbiome.

So I am very cautious about seeing a commercial stool test declare that somebody's microbiome is 62 percent healthy and then prescribing fifteen supplements to fix it.

We are learning an enormous amount but we are not yet able to interpret everything we can measure.

Does menopause actually change the microbiome?

Probably, but this needs nuance.

Sex hormones and the gut microbiome appear to have a bidirectional relationship. Hormonal changes may influence microbial communities, while gut microorganisms can participate in the metabolism and recycling of sex hormones.

Several human studies have reported differences between premenopausal and postmenopausal gut microbiomes, including changes in diversity and particular bacterial populations.

But findings are not completely consistent. Age, diet, body composition, medication, geography and lifestyle can all influence the microbiome and make it difficult to isolate menopause as the single cause.

So I would not tell you:

Your estrogen dropped, therefore your microbiome became unhealthy.

The science simply isn't that tidy.

What we can say is that menopause appears to be associated with changes in the gut microbial ecosystem and that the relationship between hormones and gut microbes is an important emerging area of women's health research.

The estrobolome is fascinating, but let's not turn it into another diagnosis

This is where the relationship becomes particularly interesting.

Estrogens are metabolised in the liver. Some are conjugated with compounds that allow them to be excreted through bile into the intestine.

Certain gut bacteria possess enzymes, including beta-glucuronidase, that can deconjugate some of these estrogen metabolites. This can allow estrogen to be reabsorbed through the intestine and returned to the circulation rather than being excreted.

The collection of microbial genes involved in estrogen metabolism has become known as the estrobolome. This gives us a genuine biological link between the gut microbiome and estrogen metabolism.

But please notice the difference between saying:

Gut microorganisms participate in estrogen metabolism.

And saying:

Your bloating means your estrobolome is broken and your estrogen isn't detoxifying properly.

We have evidence for the first statement. We do not have enough evidence to diagnose the second from ordinary digestive symptoms.

The estrobolome is an exciting research concept, not another condition you need to worry about having.

What about the intestinal barrier and "leaky gut"?

Your intestinal lining has a difficult job.

It must allow nutrients and other useful molecules to cross while maintaining a barrier against potentially harmful organisms and substances within the intestinal lumen.

This barrier is not a solid wall. Cells are connected by structures including tight junctions, and permeability is biologically regulated.

Increased intestinal permeability is a real phenomenon and has been studied in several gastrointestinal and systemic diseases.

Where things become problematic is when virtually every symptom from bloating to brain fog, weight gain and fatigue is attributed to "leaky gut."

Research has proposed that changes in estrogen signalling may influence intestinal barrier function, and menopause-related alterations in permeability are being investigated. But much of this area remains mechanistic or preliminary, and human menopause research still has important gaps.

So yes, intestinal barrier biology is real.

No, that doesn't mean every woman after 45 needs a "gut repair protocol."

Food intolerances can appear real without necessarily being allergies

Another common experience is suddenly feeling as though you cannot tolerate foods you have eaten for years.

Sometimes there is a genuine condition to identify.

Celiac disease, for example, is an autoimmune disease triggered by gluten and requires proper investigation. Lactose intolerance can occur when lactase activity is insufficient to digest lactose effectively.

But many food-related digestive symptoms are neither allergies nor permanent intolerances.

Certain carbohydrates collectively known as FODMAPs are poorly absorbed or highly fermentable and can trigger bloating, pain and altered bowel habits in susceptible people, particularly those with IBS.

The important point is that symptoms after eating a food do not automatically mean the food is damaging your gut.

And removing more and more foods can eventually create another problem: an unnecessarily restrictive diet with less fibre, less microbial substrate, poorer nutrient variety and increasing anxiety around eating.

Before removing a food permanently, I want to understand what reaction you are actually having and why.

Your digestive symptoms are clues

This is where I want to bring everything together.

If you have reflux, I want to understand what is allowing gastric contents to travel upwards. If you are constipated, I want to know whether the issue is stool consistency, slow transit, medication, thyroid function, inadequate intake or difficulty evacuating. If you are bloated, I want to know when it happens, whether constipation accompanies it and which foods or situations reliably trigger it. If you have diarrhoea, I want to know whether it is acute or chronic, whether there is urgency or pain, what medications you take and whether there are signs that something needs investigating.

And if your digestion suddenly changes after 45, I am interested in whether the menopause transition may be contributing. But I am also interested in everything else.

Menopause does not automatically explain new digestive symptoms. Coeliac disease, thyroid dysfunction, IBS, inflammatory bowel disease, gallbladder disease and other gastrointestinal conditions can develop during the same stage of life and may need proper investigation.

That is why "it's your hormones" is not a sufficient diagnosis.

When digestive changes should not be ignored

Most bloating and occasional changes in bowel habits are not signs of serious disease.

But persistent new symptoms deserve more attention, particularly when the pattern has clearly changed from what is normal for you.

Blood in the stool, black stools, unexplained weight loss, persistent vomiting, difficulty or pain with swallowing, significant abdominal pain, iron-deficiency anaemia or a persistent unexplained change in bowel habits should be medically assessed.

And if something simply feels significantly different and isn't settling, don't spend six months rotating probiotics and eliminating foods before speaking to somebody.

Sometimes the gut needs support. Sometimes it needs investigation.

Digestion after 45: what I want you to take away from this

Your digestive system has not necessarily "broken" because you reached midlife.

Digestion depends on coordinated stomach function, enzymes, bile, intestinal movement, the nervous system, pelvic floor and microbiome, and symptoms can arise when different parts of that system change.

Menopause may be one influence, particularly as we learn more about the relationship between sex hormones and the gut microbiome. But bloating isn't automatically dysbiosis, reflux isn't automatically low stomach acid, constipation isn't always lack of fibre and digestive symptoms aren't automatically menopause.

The first step is to understand the pattern.

And that is exactly what we will do next.

Next: Bloating, Constipation or Reflux? Where to Start

You can explore more articles, free and paid resources, my book and programmes in the Gut & Digestion section of Feel Good Menopause.