What Causes IBS Symptoms?
What’s Causing Your IBS?
7 Common Contributors Worth Exploring
If you’ve been diagnosed with IBS (or you’re pretty sure you have it), you already know the drill: bloating, cramping, rushing to the loo—or the total opposite—feeling stuck, sluggish, and uncomfortable for days.
But here’s something many people don’t realise: IBS describes a pattern of symptoms rather than a single underlying cause. While an IBS diagnosis can help explain what’s happening, many factors may contribute to symptoms, including diet, stress, changes in the gut microbiome, digestive function, and food sensitivities. Understanding your personal triggers is often the first step toward finding lasting relief.
So let’s change that.
In this article, we’re digging into what’s actually causing your IBS symptoms—and how to get to the root of them so you can finally get some relief.Some of these contributors are well recognised, while others remain areas of ongoing research and discussion. Some are obvious once you know them. Others might surprise you.
Key Takeaways
- IBS symptoms stem from various causes, including gut dysbiosis, food sensitivities, and stress.
- Certain carbohydrates, known as FODMAPs, can trigger symptoms in some individuals.
- The gut-brain axis links mental health and digestive issues, making stress a significant factor in IBS.
- Conditions like SIBO and Candida overgrowth may also contribute to IBS symptoms for some people.
- Identifying personal triggers and managing diet, stress, and lifestyle are key to finding relief from IBS.
Estimated reading time: 9 minutes
1. Gut Dysbiosis
Your digestive tract is home to trillions of microorganisms, collectively known as the gut microbiome. Research suggests that some people with IBS have differences in the composition of their gut bacteria compared with people who do not experience digestive symptoms.
When the balance of gut microbes changes, some people may experience symptoms such as:
• Bloating after meals
• Excess gas
• Abdominal discomfort
• Changes in bowel habits
A number of factors may influence the gut microbiome, including antibiotic use, dietary habits, illness, stress, and lifestyle factors.
What may help:
• Eating a varied, fibre-rich diet if tolerated
• Managing stress levels
• Discussing probiotics with your healthcare practitioner
• Supporting healthy digestion through regular meal patterns and mindful eating
2. Food Sensitivities You Haven’t Identified Yet
You might already know that gluten and dairy can be problematic for some people, but they’re not the only foods that may trigger IBS symptoms. Certain carbohydrates known as FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols) can be difficult for some people to digest and may contribute to bloating, abdominal discomfort, gas, and changes in bowel habits.
Common high-FODMAP foods include onions, garlic, some fruits, certain dairy products, legumes, and sugar alcohols often found in “sugar-free” products.
Research suggests that a low-FODMAP diet may help reduce symptoms in some people with IBS. The diet was originally developed by researchers at Monash University and has become one of the most widely studied dietary approaches for IBS management. However, the goal is not long-term restriction. Instead, the diet is typically used as a short-term tool to help identify personal food triggers before foods are gradually reintroduced.
How to identify potential triggers:
• Keep a food and symptom diary
• Consider a short-term low-FODMAP approach under professional guidance
• Reintroduce foods systematically to identify specific triggers
• Focus on building the most varied diet you can comfortably tolerate
Food triggers are one of the most common reasons people experience symptom flare-ups. You may also find our article on how to calm IBS flare ups naturally helpful.
3. Stress and the Gut-Brain Axis
IBS is not “all in your head,” but there is a strong connection between the brain and the digestive system. Researchers often refer to this as the gut-brain axis — the two-way communication network between your digestive tract and nervous system.
Many people notice that stress, anxiety, major life events, or even a busy schedule can make IBS symptoms worse. Stress may influence digestion, bowel habits, and how sensitive the gut becomes to discomfort.
Clues this might apply to you:
• You notice digestive symptoms before meetings, travel, or important events
• Your IBS tends to flare during stressful periods
• Symptoms improve when you’re on holiday or feeling more relaxed
What may help:
• Deep breathing exercises or mindfulness practices
• Regular walking or gentle exercise
• Prioritising good sleep habits
• Taking time each day to relax, journal, meditate, or unwind
• Developing routines that support both mental wellbeing and digestive health
Over many years in clinical practice, Eric Bakker observed that emotional stress was one of the most common triggers reported by people living with IBS.
4. SIBO (Small Intestinal Bacterial Overgrowth)
Small Intestinal Bacterial Overgrowth (SIBO) is a condition in which unusually high numbers of bacteria are present in the small intestine. Because many of its symptoms overlap with IBS, some researchers believe SIBO may play a role in a subset of people diagnosed with IBS.
Common symptoms associated with SIBO may include:
• Bloating, particularly after meals
• Excess gas
• Abdominal discomfort
• Changes in bowel habits
• Feeling unusually full after eating
Diagnosing SIBO can be challenging because symptoms often resemble other digestive conditions. Breath testing is commonly used, although diagnosis should always be interpreted alongside a person’s symptoms and medical history.
What may help:
• Working with a qualified healthcare practitioner
• Identifying and addressing potential underlying causes
• Following an appropriate dietary approach
• Supporting overall digestive and gut health
In clinical practice, Eric Bakker frequently saw symptoms of SIBO overlap with IBS, making careful assessment of digestive symptoms an important part of identifying potential underlying causes.
5. Candida Overgrowth
Candida albicans is a yeast that naturally lives in the digestive tract and other parts of the body. Some practitioners and researchers believe that an overgrowth of Candida may contribute to digestive symptoms in certain individuals, although its exact role in IBS remains an area of ongoing discussion and research.
When Candida overgrowth is suspected, people may report symptoms such as:
• Bloating and digestive discomfort
• Excess gas
• Sugar cravings
• Fatigue or brain fog
• Recurrent fungal or yeast-related infections
Factors that may contribute to an imbalance in gut microorganisms include repeated antibiotic use, high-sugar diets, chronic stress, and underlying digestive disturbances.
What may help:
• Reducing excess sugar and highly processed foods
• Supporting a balanced and diverse gut microbiome
• Addressing underlying digestive health concerns
• Working with a qualified healthcare practitioner to determine the most appropriate approach
If you’re interested in learning more, see our article: What Is Candida Overgrowth? (And What You Can Do About It)
6. Low Stomach Acid
Low stomach acid is sometimes discussed as a possible contributor to digestive symptoms such as bloating, fullness after meals, and discomfort after eating. While it is not considered a primary cause of IBS, some practitioners believe that inadequate stomach acid may affect digestion in certain individuals.
Possible signs associated with low stomach acid may include:
• Bloating or fullness after meals
• Frequent belching
• A sensation that food is sitting heavily in the stomach
• Digestive discomfort after eating
What may help:
• Chewing food thoroughly and eating more slowly
• Avoiding large, rushed meals
• Creating a calm environment before eating
• Discussing digestive support options with a qualified healthcare practitioner
Good digestion begins before the first bite. Taking a few moments to slow down, breathe deeply, and focus on your meal may help support healthy digestive function.
7. Increased Intestinal Permeability (“Leaky Gut”)
Some researchers use the term increased intestinal permeability to describe changes in the gut barrier that may occur in certain digestive conditions. You may also hear this referred to as “leaky gut.”
While research into intestinal permeability is ongoing, some practitioners believe that changes in the gut barrier may contribute to digestive symptoms and food sensitivities in certain individuals.
What may help:
• Eating a balanced, minimally processed diet
• Managing stress and prioritising good sleep
• Supporting a healthy and diverse gut microbiome
• Working with a qualified healthcare practitioner to address underlying digestive concerns
You Deserve More Than Symptom Management
IBS can be frustrating because symptoms often come and go, and what works for one person may not work for another. Understanding your personal triggers—whether they involve diet, stress, gut microbiome changes, food sensitivities, or other digestive factors—is often an important step toward long-term symptom improvement.
While there is no single cause of IBS, many people find that a combination of dietary changes, stress management, healthy lifestyle habits, and digestive support can make a meaningful difference over time.
If you haven’t already, you may find our article on How to Calm IBS Flare Ups Naturally helpful for practical day-to-day strategies to support digestive comfort.
For those looking to support their digestive health further, the Yeastrix Gut Restore Kit combines digestive enzymes, probiotics, and targeted nutritional support designed to complement a gut-health-focused lifestyle.
Frequently Asked Questions About IBS Symptoms
Stress doesn’t directly cause IBS, but it can trigger or worsen symptoms in many people through the gut-brain connection. Many people notice their symptoms become more noticeable during stressful periods and improve when stress levels are lower.
Common triggers include high-FODMAP foods such as onions, garlic, some fruits, legumes, dairy products, and sugar alcohols. However, triggers vary from person to person, which is why keeping a food diary can be helpful.
Yes. SIBO and IBS share many similar symptoms, including bloating, gas, abdominal discomfort, and changes in bowel habits. This overlap is one reason why some people investigate SIBO as a possible contributor to their digestive symptoms.
IBS is a complex condition with multiple possible contributing factors. Some practitioners believe Candida overgrowth may contribute to symptoms in certain individuals, but it is unlikely to be the sole explanation for every case of IBS.
Many people find that identifying food triggers, managing stress, improving sleep, exercising regularly, and supporting overall digestive health can help reduce symptom frequency and severity over time.
Food sensitivities are commonly reported by people with IBS. While triggers vary from person to person, some individuals notice symptoms after consuming high-FODMAP foods, dairy products, gluten-containing foods, or certain food additives.
Related Readings
Want to dive deeper into the naturopathic approach to IBS? Check out this detailed guide by Eric Bakker, ND, on the treatment of Irritable Bowel Syndrome using natural and functional medicine principles. He breaks down the root causes, how Candida may be involved, and key steps for long-term relief.
This article is intended for educational and informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with a qualified healthcare provider before starting any new treatment or supplement, especially if you have a pre-existing medical condition or are taking medication. The recommendations here reflect a naturopathic approach and are not meant to replace conventional care when it is required. Individual results may vary.
