What is Causing my Frustrating IBS?


So you’ve been diagnosed with IBS- Irritable Bowel Syndrome. Essentially, it’s just labeling what you already knew…your bowels aren’t functioning correctly and you have digestive distress because of it!  What you really want to know is WHY is my bowel “irritable” and what caused it. Digestive disorders can be perplexing, especially when acronyms are thrown around like IBD (Inflammatory Bowel Disease) and IBS (Irritable Bowel Syndrome). Before we talk about potential causes of IBS, let’s distinguish the difference between IBD and IBS. While these conditions share some common symptoms, they are distinctive with different underlying causes and management strategies. So it’s important to understand the difference and be diagnosed appropriately.

What is IBD and IBS?

Inflammatory Bowel Disease (IBD):

IBD encompasses chronic inflammatory conditions of the digestive tract, with two primary subtypes—Crohn’s disease and ulcerative colitis. These conditions involve inflammation that extends beyond the surface layer of the digestive tract, leading to damage and complications. Common symptoms include abdominal pain, diarrhea, weight loss, fatigue, and in severe cases, rectal bleeding.

Irritable Bowel Syndrome (IBS):

IBS, on the other hand, is classified as a functional gastrointestinal disorder. Unlike IBD, IBS doesn’t involve inflammation or structural damage to the digestive tract. It is characterized by a group of symptoms, including abdominal pain, bloating, and changes in bowel habits. IBS is often diagnosed based on the presence of specific criteria known as the Rome Criteria.

How the Rome Criteria is Often Used for IBS Diagnosis

The Rome Criteria outlines specific criteria for the diagnosis of functional gastrointestinal disorders, such as IBS. These criteria focus on the presence, duration, and characteristics of symptoms, ensuring a standardized approach to diagnosis.

Duration of Symptoms:

The criteria specify the minimum duration for which symptoms must be present to qualify for a diagnosis. For IBS, symptoms typically need to be present for a specified duration, often at least six months, to be considered in the diagnostic evaluation.

Characteristic Symptoms:

The Rome Criteria delineate the characteristic symptoms required for a diagnosis. For IBS, these include abdominal pain or discomfort associated with changes in bowel habits, such as altered frequency or consistency of stools.

Exclusion of Structural Abnormalities:

The criteria emphasize the importance of excluding structural abnormalities or other medical conditions that might explain the symptoms. This ensures that the diagnosis is based on functional disturbances rather than structural issues in the gastrointestinal tract.

For more on Rome Criteria, visit this site.

Distinguishing and Differentiating Factors: IBD vs. IBS


The presence of inflammation distinguishes IBD from IBS. In IBD, inflammation is a hallmark feature and can be visualized through medical imaging and endoscopic procedures. IBS, on the other hand, does not involve inflammation or structural damage to the digestive tract.

Structural Damage:

IBD can lead to structural damage in the digestive tract, including ulcers, strictures, and fistulas. In contrast, IBS does not cause such structural changes, and diagnostic tests like colonoscopies typically appear normal.

Diagnostic Criteria:

IBS is diagnosed based on the Rome Criteria as mentioned above. In contrast, IBD is diagnosed through a combination of clinical evaluation, imaging studies, endoscopy, and histopathology.

Genetic Factors:

Both IBD and IBS have genetic components, but the genetic basis for IBD is more clearly defined. Functional medicine considers genetic factors in both conditions but may place more emphasis on genetic testing in IBD cases.

So What Causes IBS?

Functional medicine recognizes that IBS is not a one-size-fits-all condition but rather a syndrome with diverse and interconnected causes. The multifactorial nature of IBS means that a combination of genetic, environmental, lifestyle, and gut-related factors may contribute to its development and persistence.

Potential Cause of IBS: Gut Microbiome Imbalance

The gut microbiome, a complex community of microorganisms residing in the digestive tract, plays a pivotal role in IBS. Functional medicine highlights the importance of maintaining a balanced microbiome for optimal digestive health. Imbalances, such as dysbiosis (an overgrowth or imbalance of certain bacteria), can disrupt the delicate harmony in the gut and contribute to IBS symptoms.

Functional medicine practitioners often recommend interventions to restore balance, including probiotics, prebiotics, and dietary modifications. Targeting the microbiome aims to alleviate symptoms and address the root cause of IBS for many individuals.

Leaky Gut

Leaky gut, or intestinal permeability, is a term used in functional medicine to describe a condition where the lining of the intestines becomes more porous, allowing undigested food particles, toxins, and bacteria to leak into the bloodstream. In a healthy gut, tight junctions between cells in the intestinal lining act as barriers, controlling the passage of nutrients while preventing the entry of harmful substances.

Functional medicine attributes leaky gut to various factors, including chronic stress, poor diet, infections, and imbalances in the gut microbiome. When these factors compromise the integrity of the intestinal barrier, it can lead to inflammation and trigger an immune response.


Hypochlorhydria refers to a condition where the stomach produces insufficient hydrochloric acid. This vital stomach acid plays a crucial role in breaking down food, facilitating nutrient absorption, and preventing infections by sterilizing ingested substances. Hypochlorhydria may result from various factors, including chronic stress, aging, nutritional deficiencies, and certain medications.

Food Sensitivities and Intolerances Causing IBS Symptoms

Sensitivities to certain foods or components in the diet can trigger or exacerbate IBS symptoms. Functional medicine approaches IBS by identifying and addressing food sensitivities, which may involve laboratory testing or elimination diets. Common culprits include gluten, dairy, FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), and artificial additives.

Personalized nutrition plans, tailored to an individual’s specific sensitivities, are a cornerstone of functional medicine interventions for IBS. Eliminating trigger foods helps reduce inflammation, alleviate symptoms, and improve overall gut health.

Gut-Brain Axis Dysfunction

The intricate communication between the gut and the brain, known as the gut-brain axis, is another focal point in the functional medicine understanding of IBS. Stress and emotional factors can influence gut function, and individuals with IBS often report symptom exacerbation during times of stress or anxiety.

Functional medicine emphasizes the importance of addressing stress through techniques such as mindfulness, relaxation exercises, and cognitive-behavioral therapy. By managing the gut-brain axis, practitioners aim to reduce the impact of psychological factors on IBS symptoms.

Alterations in Gut Motility:

Dysregulation of gut motility, the coordinated movement of muscles in the digestive tract, is a common feature in IBS. Some individuals experience constipation, while others deal with diarrhea or a combination of both. 

Dietary interventions, lifestyle modifications, and specific supplements may be recommended to regulate gut motility and alleviate symptoms. Understanding the individual patterns of gut dysfunction is crucial in tailoring interventions for optimal effectiveness.

Small Intestinal Bacterial Overgrowth (SIBO):

Small Intestinal Bacterial Overgrowth occurs when there is an abnormal increase in the number or type of bacteria in the small intestine. SIBO has been associated with IBS, particularly in cases where symptoms are related to the consumption of certain carbohydrates. Functional medicine practitioners may consider SIBO testing and employ targeted interventions such as antimicrobial treatments and dietary changes. Recognizing and addressing SIBO contributes to the overall functional medicine strategy for IBS, as it helps rebalance the gut microbiome and reduce symptoms related to bacterial overgrowth.

Genetic Factors:

While IBS is not directly inherited, genetic factors may contribute to an individual’s susceptibility to developing the condition. Functional medicine practitioners may explore genetic testing to identify specific genetic variations related to gut function and inflammation. Genetic insights can guide personalized interventions and lifestyle modifications tailored to an individual’s unique genetic makeup, optimizing their response to treatment and symptom management.

Environmental Triggers:

Environmental factors, such as exposure to toxins, infections, or a history of antibiotic use, can influence the development of IBS. Functional medicine takes a holistic approach, considering environmental triggers that may have contributed to gut dysregulation. Addressing environmental triggers involves a thorough evaluation of an individual’s history and lifestyle. Strategies may include detoxification protocols and lifestyle modifications to reduce ongoing exposure to potential triggers.

Identifying Root Cause Can Help Create a Healing Pathway

These are just some common causes, but this list is not extensive. The functional medicine perspective on the causes of Irritable Bowel Syndrome recognizes the intricate interplay of various factors, acknowledging that each individual’s experience with IBS is unique. By addressing the multifaceted nature of this condition, functional medicine practitioners aim to uncover the root causes and provide personalized interventions that target specific contributing factors.

From restoring balance to the gut microbiome and identifying and eliminating trigger foods to addressing the gut-brain axis and considering genetic influences, functional medicine offers a comprehensive and individualized approach to IBS management. It emphasizes the importance of understanding the person as a whole, considering their genetics, lifestyle, environment, and unique physiological responses.

If you suspect you have IBS or are struggling with gastrointestinal symptoms, we can work together to gain insight into the root causes of your condition. Working collaboratively with healthcare professionals, both in conventional and functional medicine, can lead to a more holistic and effective approach to managing IBS and improving overall digestive health.




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The older Linda gets, the longer she applies holistic strategies of diet and lifestyle and the better she feels! Learn more about her story.

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