What Is IBS?

Irritable Bowel Syndrome (IBS) is one of the most common digestive conditions in the United States, affecting an estimated 10–15% of adults. Yet, despite how widespread it is, IBS remains poorly understood in conventional medicine. Many patients are told their symptoms are “just stress” or are given medications that mask symptoms without addressing the underlying cause.

At Sheen Vein (Aesthetics and Functional Medicine) in St. Louis, we take a different approach. We view IBS not as a single disease but as a collection of symptoms with multiple possible root causes. This allows us to personalize treatment — and in many cases, dramatically improve quality of life.

Common Symptoms of IBS

IBS is a functional gastrointestinal disorder, meaning that the structure of the gut looks normal on tests, but its function is impaired. Symptoms can range from mild to debilitating and may fluctuate over time. Common signs include:

• Abdominal pain or cramping, often relieved after a bowel movement
• Bloating and excessive gas
• Changes in stool frequency or consistency (constipation, diarrhea, or both)
• Urgency to have a bowel movement
• A feeling of incomplete evacuation
• Mucus in stool

IBS is typically classified into subtypes:

• IBS-C: Constipation-predominant
• IBS-D: Diarrhea-predominant
• IBS-M: Mixed constipation and diarrhea
• IBS-U: Unsubtyped, where symptoms don’t fit neatly into the other categories

Why IBS Happens: The Functional Medicine View

From a functional medicine perspective, IBS is not “all in your head.” Instead, it often results from a complex interplay of digestive, immune, microbial, and nervous system factors. Some of the most common root causes we see in our St. Louis practice include:

1. Gut Dysbiosis

An imbalance between beneficial and harmful bacteria in the intestines can disrupt digestion, trigger inflammation, and produce gas that causes bloating and pain. Dysbiosis is common after antibiotic use, food poisoning, or chronic stress.

2. Small Intestinal Bacterial Overgrowth (SIBO)

In SIBO, bacteria that normally live in the large intestine migrate into the small intestine, fermenting food too early in the digestive process. This leads to bloating, gas, diarrhea, or constipation. Many studies show a significant overlap between SIBO and IBS.

3. Post-Infectious IBS

Some people develop IBS after a gastrointestinal infection such as traveler’s diarrhea or food poisoning. The infection can trigger lingering changes in gut motility, nerve signaling, and microbial balance.

4. Food Sensitivities

Unlike food allergies, which cause immediate immune reactions, sensitivities create delayed symptoms that can be harder to link to a specific food. Gluten, dairy, soy, and certain fermentable carbohydrates (FODMAPs) are common culprits.

5. Low Stomach Acid or Poor Digestive Enzyme Output

If food isn’t broken down properly in the stomach or pancreas, it can ferment in the gut, feeding harmful bacteria and triggering IBS symptoms.

6. Gut-Brain Axis Dysregulation

The gut and brain communicate through the vagus nerve and other pathways. Stress, anxiety, or trauma can disrupt this signaling, altering motility and sensitivity in the digestive tract.

7. Micronutrient Deficiencies

Magnesium, zinc, and vitamin D deficiencies can impair digestive function and immune regulation in the gut.

The Role of Stress in IBS

Stress does not cause IBS, but it can make symptoms worse. The gut has its own nervous system — the enteric nervous system — which is highly sensitive to stress hormones. Chronic stress can:

• Slow or speed up gut motility
• Increase intestinal permeability (“leaky gut”)
• Alter microbial balance
• Heighten pain perception in the gut

That’s why managing stress is an important part of any IBS treatment plan, alongside targeted digestive therapies.

Conventional IBS Treatment Limitations

Standard treatment for IBS often focuses on symptom control:

• Antispasmodic drugs for cramping
• Laxatives for constipation
• Anti-diarrheal medications
• Low-dose antidepressants for pain perception
• Dietary advice to “eat more fiber”

While these can help temporarily, they don’t identify or resolve the root causes. As a result, many patients cycle through medications and diets without lasting relief.

The Functional Medicine Approach to IBS

At Sheen Vein (Aesthetics and Functional Medicine), our goal is to uncover the factors driving your IBS so we can treat it at the source. Our process often includes:

Step 1: Comprehensive History and Symptom Mapping

We dig deep into your medical history, diet, travel, stress levels, and past infections to find patterns.

Step 2: Advanced Testing

We may recommend:

• Comprehensive stool analysis for bacteria, yeast, parasites, and inflammation
• SIBO breath testing
• Food sensitivity testing
• Nutrient panels
• Stomach acid and enzyme function assessments

Step 3: Targeted Gut Healing Protocol

Depending on your results, we may use:

• Antimicrobial herbs or prescription agents to reduce bacterial overgrowth
• Probiotics and prebiotics to restore healthy flora
• Digestive enzymes or betaine HCl to improve digestion (learn more in our blog on What Betaine Does for Digestion)
• Anti-inflammatory nutrients like L-glutamine, zinc carnosine, and omega-3s to repair the gut lining

Step 4: Personalized Nutrition Plan

We help patients trial evidence-based approaches such as the low-FODMAP diet, gluten elimination, or gut-soothing foods to reduce symptoms while healing takes place.

Step 5: Gut-Brain Axis Support

This may include vagus nerve stimulation exercises, mindfulness, gentle yoga, or targeted adaptogenic herbs to reduce the gut’s stress response.

A Real-Life Success Story

A 36-year-old patient came to us after struggling with IBS-D for 8 years. She had tried multiple diets, fiber supplements, and prescription medications with little relief. Testing revealed methane-dominant SIBO, low stomach acid, and a sensitivity to dairy.

We implemented a 12-week program including antimicrobial therapy, betaine HCl with meals, dairy elimination, and stress management techniques. By the end of her program, her bowel movements normalized, bloating resolved, and she was able to reintroduce many foods without triggering symptoms.

Long-Term Outlook for IBS Patients

The encouraging news is that IBS is not a life sentence. While symptoms can be persistent, addressing the underlying imbalances often leads to dramatic improvement. Many patients are able to significantly reduce or eliminate their symptoms and regain a sense of control over their lives.

When to Seek Help

If you have persistent digestive symptoms — especially if they interfere with your daily activities — it’s worth investigating the root cause. IBS shares symptoms with other, more serious conditions like inflammatory bowel disease and celiac disease, so professional evaluation is important.

At Sheen Vein (Aesthetics and Functional Medicine), we offer both in-office and telemedicine consultations for patients in St. Louis and beyond. Our team is committed to helping you uncover the “why” behind your symptoms and build a personalized, effective treatment plan.

Bottom Line: IBS is common, but it’s not “just in your head” and it’s not something you have to live with forever. By uncovering root causes such as dysbiosis, SIBO, food sensitivities, and gut-brain axis imbalances, functional medicine offers hope for long-term relief.

Internal Link Opportunities:

• Link “gut dysbiosis” to your blog on Fixing Gut Dysbiosis to Help Autoimmune Issues.
• Link “betaine HCl” to your blog on What Betaine Does for Digestion.
• Link “nutrient deficiencies” to your blog on Nutritional Deficiencies and Their Impact on Collagen Production.
• Link “stress management techniques” to your blog on How Functional Medicine Can Help Brain Fog.

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