Digestive health is often overlooked – until something goes wrong.
In this episode of the Her Health Podcast, gastroenterologist Dr Thania Kahn explains that most gut issues like IBS, bloating and food intolerances are driven by diet, stress and the gut–brain connection rather than single causes, and how many of these symptoms can be managed effectively with evidence-based dietary, lifestyle, and medical approaches.
From bloating and food intolerances to IBS and more serious conditions, your gut plays a central role in how you feel every day.
Rapid Fire: Gut Health Truths, Rated
To kick things off, we asked Dr Thania Kahn to rate common gut health habits from 0 (not beneficial for your gut) to 10 (great for your gut) – and some of the answers might surprise you:
- Being exposed to dirt as a child – 8/10
- Daily bowel movements – 1/10. Anywhere from 2–3 times a day to 2–3 times a week can be completely normal.
- Caffeine on an empty stomach – 5/10. If you tolerate it well, it’s generally fine.
- Caffeine enemas – 0/10. A firm no.
- Magnesium – 8/10. Magnesium glycinate supports sleep, while magnesium citrate can help relieve constipation.
- Probiotics – It depends. Corrects gut dysbiosis, but they aren’t one-size-fits-all.
- Colonoscopy at age 45 – 10/10. A must. Early screening is key, especially with rising rates of colorectal cancer in younger populations.
- Fibre in your diet – 8/10. Essential for gut health, glucose control, and cardiovascular health.
- At-home gut microbiome tests – 0/10. Interesting, but not yet clinically useful.
What Does a Gastroenterologist Do?
A gastroenterologist is a specialist physician who diagnoses and treats disorders of the digestive system – everything from the mouth all the way through to the intestines to the rectum, including organs like the liver, pancreas, and gallbladder.
After over a decade of intensive training, including an internal residency in cardiology, nervous, endocrine, and renal systems, as well as a gastroenterology fellowship, Dr Kahn manages conditions such as:
- Irritable bowel syndrome (IBS)
- Inflammatory bowel disease (IBD)
- Reflux and indigestion
- Chronic constipation or diarrhoea
- Food intolerances and allergies
Thania also performs procedures like gastroscopies and colonoscopies to investigate symptoms more deeply.
What’s “Normal” When It Comes to Your Gut?
When it comes to gut health, there’s a wide range of what’s considered normal. Thania noted how:
- You don’t need to have a bowel movement every day – anything from 2–3 times a day to 2–3 times a week can be healthy.
- If you are feeling tired after eating – That’s called postprandial fatigue – and it’s completely normal.
- Having coffee on an empty stomach is fine if you can tolerate it.
Gut Health Essentials That Actually Matter
1. Fibre is foundational and supports:
- Gut motility
- Blood sugar balance
- Heart health
But the key is to introduce it slowly to avoid bloating.
2. Magnesium has real benefits
- Magnesium glycinate → may support sleep
- Magnesium citrate → supports digestion and may relieve constipation
3. Probiotics: helpful for gut dysbiosis, but not a one-size-fits-all
While Thania does not consider them a one-size-fits-all, probiotics do have strong clinical evidence in a few cases, including:
- Antibiotic-associated diarrhoea
- Certain inflammatory bowel conditions
What Are the Red Flags for Gut Health Issues?
Dr Kahn stressed that if you experience any of the following, it’s important to seek medical advice:
- Sudden changes in bowel habits
- Rectal bleeding
- Unexplained weight loss
- Persistent and worsening abdominal pain
- Difficulty swallowing
- Ongoing vomiting or anaemia
What’s the Difference Between Food Allergy and Food Intolerance?
This is where a lot of confusion exists. Dr Kahn stressed the importance of knowing the difference between food intolerance and a food allergy:
Food intolerances:
- Not immune-related
- Often caused by enzyme deficiencies (e.g. lactose intolerance)
- Can be pharmacological – caused by preservatives, aspirin allergy etc.
- Symptoms: bloating, discomfort, diarrhoea
- Not life-threatening
Food allergies:
- Immune-mediated (IgE-mediated, soon after ingestion vs non-IgE- mediated, 24 hours after ingestion)
- Can trigger severe reactions like hives, diarrhoea, or anaphylaxis
- Require proper diagnosis and management
- Can be life threatening
Importantly, Thania noted that intolerances can often improve over time – especially when managed correctly.
What Is Lactose Intolerance and How Should It Be Managed?
Lactose intolerance is a common digestive condition caused by difficulty digesting dairy. It affects an estimated 60–70% of adults and occurs when the body doesn’t produce enough of the enzyme lactase to properly break down lactose, the natural sugar found in milk and dairy products. This can lead to symptoms like bloating, abdominal discomfort and diarrhoea after consuming dairy.
Dr Kahn explained how some people find relief with lactase enzyme supplements, while others benefit from reducing, modifying, or cutting out dairy from their diet.
Gluten: Should You Avoid It?
Dr Kahn explained how for the majority of people, gluten is not harmful – and unnecessarily eliminating it isn’t beneficial. However, it is important to note:
Coeliac disease is a serious autoimmune condition requiring a strict lifelong gluten-free diet. For coeliacs, gluten ingestion can damage the small intestines and can cause chronic inflammation and malabsorption of nutrients.
Gluten intolerance (non-coeliac gluten sensitivity) causes symptoms such as bloating, discomfort, fatigue but doesn’t damage the gut.
“Gluten is a safe dietary protein in over 99% of the population. If you do not have coeliac or a wheat allergy, it’s unnecessary to eliminate it from your diet.”
IBS vs IBD: Understanding the Difference
IBS and IBD are often confused, but they are very different conditions.
IBS (irritable bowel syndrome):
- Previously known as a functional gut disorder, now linked to the gut-brain axis.
- Caused by an imbalance between the gut, brain, and nervous system.
- No structural damage to the gut.
- Hallmark symptoms: bloating, abdominal pain, changes in bowel habits – related to food.
- Can be managed with lifestyle and dietary changes.
IBD (Inflammatory Bowel Disease):
- A chronic autoimmune condition (e.g. Crohn’s disease, ulcerative colitis).
- Caused by the body’s cell lining attacking itself.
- Causes inflammation and damage to the digestive tract.
- Hallmark symptoms: Severe abdominal pain, rectal bleeding, weight loss, fevers, anaemia.
- Requires medical treatment and monitoring.
How Does the Gut-Brain Connection Affect Gut Health?
Your gut and brain are constantly communicating.
- Stress can directly trigger gut symptoms.
- IBS is strongly linked to anxiety and emotional health.
- The gut produces many neurotransmitters, including serotonin.
- This is why managing stress is just as important as managing diet.
How to Manage IBS Effectively
There’s no one-size-fits-all approach, but treatment typically includes:
Dietary changes
- Low FODMAP diet – avoiding foods that are Fermentable, Oligosaccharides, Disaccharides, Monosaccharides, and Polyols – sugars that are non-absorbable in the small intestine – to support symptoms
- Identifying personal triggers (elimination diet)
- Keeping a food diary
- Including fibre (soluble or insoluble as needed) in your diet
- Seeing a dietitian for guidance
Stress management
- Therapy (including Cognitive Behavioural Therapy)
- Meditation, yoga, and breathing exercises
- Targeted support (pharmacological medication when needed)
Supplements
- Medications (for bloating, gut motility, diarrhoea, constipation)
- Consistency and patience are key – IBS management is a process, not a quick fix.
When Should You Get a Colonoscopy?
Thania explained how screening guidelines now recommend a colonoscopy at age 45, even without symptoms due to rising rates of colorectal cancer in younger populations – potentially linked to:
- Ultra-processed diets
- Low fibre intake
- Microbiome disruption
- Environmental factors like microplastics
The primary risk factor according to Dr Kahn? A Westernised diet including ultra-processed foods, high in fat and sugar, and low in fibre.
Thania noted how this, along with antibiotic use and exposure to microplastics, disrupts the microbiome, causes cell damage, increases inflammation, and is a major driver of modern digestive issues.
Gut health is complex, deeply personal, and influenced by far more than just what you eat. As Dr Thania Khan highlights, understanding your body, recognising red flags, and taking a balanced, evidence-based approach is key.
From managing stress and supporting your microbiome to avoiding unnecessary restrictions, small, consistent changes can make a meaningful difference in how you feel every day.
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This content is for informational purposes only and does not constitute medical advice. Always consult with your healthcare provider before starting any new supplement, especially if you are pregnant, nursing, have a medical condition, or are taking prescription or chronic medication.
