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Alyssa Simpson RD, CDE, CLT
Alyssa Simpson

(602) 422-9800

Sibo Doctor Approved
certified gastrointestinal nutritionist
Sibo Doctor Approved
certified gastrointestinal nutritionist

What Is a Functional Nutritionist and Why Is One Essential for IBS and SIBO

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Table of Contents

What is a Functional Nutritionist?

A functional nutritionist is a healthcare professional – usually a registered dietitian, although not always –  who takes a holistic approach to nutrition, focusing on finding and addressing the underlying causes of health concerns rather than just managing symptoms.

Functional nutritionists use evidence-based strategies that include dietary changes, lifestyle adjustments, and therapeutic supplements to improve overall well-being by supporting the body’s natural processes and functions to achieve optimal health.

Their specialized training in functional medicine principles allows them to tailor their approach to each individual’s needs, aiming to restore balance and promote long-term wellness.

The Limitations of Standard Medicine for Gut Issues

The standard medicine approach often falls short with functional digestive disorders like Irritable Bowel Syndrome (IBS) and Small Intestinal Bacterial Overgrowth (SIBO) because it mainly focuses on dealing with symptoms instead of addressing the root causes of these issues.

Additionally, the treatments they offer might only give temporary relief and sometimes come with unwanted side effects, without really getting to the root of the problem like underlying imbalances in the gut microbiome, gut-brain axis, or other contributing factors that functional nutrition practitioners aim to address.

Trevor’s Journey: Finally Finding Hope and Relief Through Functional Nutrition

Trevor’s gut issues began unexpectedly in his early 20s, shortly after getting married.

What started as minor stomach discomfort quickly escalated into persistent episodes of diarrhea.

Trevor attributed this change to adopting some of his wife’s unhealthy eating habits, alongside getting food poisoning around the same time.

However, he didn’t connect this incident to what would become a 19-year battle with severe IBS until seeking my help (initially, Trevor assumed that his post-marriage junk food indulgence was solely to blame.)

As Trevor’s symptoms worsened, they significantly impacted his professional life, particularly his frequent travel and public speaking engagements.

The uncertainty of when he might need to rush to the bathroom terrified him.

Despite seeking help from doctors, Trevor felt increasingly desperate, even contemplating extreme measures like wearing adult diapers or resorting to a colostomy bag.

After years of struggle, Trevor became frustrated with his gastroenterologist, who reminded him of a previous referral to me, which he had never followed up on.

Trevor admits he was skeptical about seeing a dietitian, having self-limited his diet to chicken and rice for many years to manage his symptoms.

“I heard the word dietitian and immediately I was like, I don’t need someone to write me a diet plan and tell me don’t eat this, don’t eat that.”

Trevor finally agreed to meet with me and scheduled his 15-minute free call, viewing it as a final attempt after exhausting other options. His life was about to change!

Much to his surprise, after chatting with me about his issues, Trevor felt hopeful and immediately enrolled to work with me.

“For the first time in 19 years of my life, I got off that call and I went to my wife and said, I have hope for the first time. I feel like I have hope.” 

Shortly after starting our work together, he discovered that the dietary changes and supplements I recommended quickly began to alleviate his symptoms.

Through specialized functional lab testing, we identified that Trevor had SIBO, a condition characterized by an overgrowth of bacteria in the small intestine.

With targeted natural interventions, we quickly resolved his diarrhea and restored normal bowel movements, a relief he hadn’t experienced in nearly two decades.

Additionally, we balanced his gut bacteria using natural supplements.

By combing through Trevor’s medical history, we uncovered various factors contributing to his gut issues, including past medications, the previous food poisoning incident, and prior surgeries.

I explained to Trevor that while eating junk foods may exacerbate SIBO once it’s present, they are unlikely to be the root cause of SIBO.

Today, Trevor no longer lives in fear of frequent bathroom trips or accidents.

He can enjoy a regular diet without the worry of triggering his symptoms. He is back to eating a normal diet, eating out, and enjoying occasional treats without worrying it will send him running to the bathroom.

“At times I get emotional about it because I am so excited for what my future holds now, where I was so distraught with the life I was living.”

Trevor’s journey demonstrates the importance of looking beyond standard medical testing when it comes to gut issues and addressing underlying functional issues in the gut.

His experience is a testament to the value of persistence in seeking answers, even in the face of depression and despair.

I am so pleased to have been able to help him, along with the hundreds of other clients I have helped find lasting relief after years of searching for solutions.

Why Functional Nutrition is so Important for IBS and SIBO

Functional digestive disorders like IBS and SIBO are conditions that affect the normal functioning of the digestive system without causing structural changes. This is why so often the doctor’s testing will tell you nothing is wrong even though you’re feeling awful.

IBS is characterized by symptoms like abdominal pain, bloating, constipation, and/or diarrhea, that can be different for each person and change over time. These symptoms happen because the brain and gut aren’t communicating well, the gut doesn’t move food along properly, the nerves in the gut are too sensitive, or the balance of gut bacteria is off.

SIBO happens when there are too many bacteria growing in the small intestine, causing you to feel bloated, gassy, uncomfortable, or painful. The abundance of bacteria can interfere with your ability to absorb nutrients and make your gut inflamed.

Functional nutrition is critical for conditions like IBS, SIBO, and other digestive issues because it looks at how your hormones, gut, and brain talk to each other, how well your gut moves food along, how sensitive your gut is, and how balanced the bacteria in your gut are.

Because everyone’s gut is different, it’s important to find out what’s really causing the problem. Standard medicine doesn’t always do this well. Functional nutrition figures out what’s wrong and creates a plan just for you, which can help fix the problem and keep you healthy in the long run.

My Story

My first 10 years as a dietitian were spent focusing mainly on general wellness and diabetes.

Then, in 2013, I pursued my dream and started my private practice specializing in gut health and food sensitivities.

Partnering with Arizona Digestive Health brought quick success, but the stress of starting a business and learning a new specialty caught up with me fast.

Within a year, I had developed severe acid reflux which was making me completely miserable. My throat felt like it was on fire all the time, I couldn’t sleep because I would cough whenever I laid down, and my condition was causing damage to my throat and esophagus.

Being a new gut health dietitian, I knew exactly what foods to eliminate to help, and I did just that. And it did help.

But, my excitement about that was short-lived as I quickly grew tired of having to restrict my diet.

As a dietitian, we are taught “everything in moderation,” but that is just NOT TRUE when certain foods are making you sick.

I was hearing the same response from my clients as I was helping them implement nutrition therapies like elimination diets.

They, like me, were initially THRILLED to be feeling so much better.

But before long, they quickly grew tired of feeling restricted and they would ask me “Am I going to have to eat like this FOREVER?” 

And to be honest, I was wondering the same thing myself.

What turned everything around for me was when I realized stress was at the root of my troubling symptoms.

I also discovered I had developed food sensitivities as a result of the stress that were now perpetuating my condition.

And because of the damage to my tissues from the acid, I was opening up the potential for a cascade of worsening issues.

It wasn’t until I really got serious about removing my triggers, addressing the root cause of what was causing my digestive imbalance, and taking steps to heal and restore what had been damaged, that things finally turned around for me.

I became determined to learn as much as possible about digestive health and I pursued advanced training in integrative and functional nutrition, and gastrointestinal nutrition, and have been trained by the top university and experts in IBS & SIBO.

After facing my own health challenges and finding relief through personalized nutrition interventions, I became dedicated to sharing this transformative approach with others.

As a functional nutrition therapy practitioner, I’ve refined a system that has consistently delivered remarkable results for my clients.

This journey has reinforced my belief in the power of addressing root causes, rather than just managing symptoms, and I’m committed to helping others reclaim their vitality and wellness through tailored nutrition and lifestyle interventions.

The 5 Rs of Functional Nutrition

Now, I’m excited to share with you the cornerstone of functional nutrition: the 5 Rs process. Let’s talk about how the role that each step in this framework plays in restoring balance and promoting digestive health.

I want to stress that one of the most common mistakes I see is attempting to tackle these steps out of sequence or incompletely.

For example, if you start by buying a supplement promoted for “gut healing,” you’re skipping ahead to the repair phase without addressing the initial steps of removal of problematic foods and microbes, replacement of crucial enzymes and nutrients, and reinoculation of beneficial bacteria.

It’s like trying to douse a fire with water while someone continues to pour gasoline on it. To achieve lasting and effective results, it’s essential to complete each step in the proper order.


Identify and eliminate triggers such as food intolerances and sensitivities, and harmful microbes that may worsen digestive symptoms.

In this step, we calm down symptoms quickly and start cleaning up what is out of balance.


Incorporate any necessary nutrients, enzymes, and acids that may be deficient.

This can involve supplementation or dietary changes to support optimal digestion and nutrient absorption and repletion.


Reestablish a healthy balance of gut microbiota by introducing beneficial bacteria through probiotics, prebiotics, and fermented foods.

This step helps to restore gut health and immune function now that the disrupting factors have been removed.


Now that we’ve stopped adding fuel to the fire and optimized digestion, nutrient levels, and microbial balance, it’s time to start repairing.

In this step, we focus on healing the gut lining using nutrient-rich foods and possibly supplements that support tissue repair.

This is crucial for sealing up the gut lining to prevent further problems caused by leaky gut.


Now, in the final step of the 5 R’s, we’re shifting gears to reintroducing those foods you’ve been missing so much!

At this point, symptoms have settled, and we’ve sorted out any nutrient deficiencies and restored the balance of good bacteria in the gut.

We can start reintroducing foods cautiously and systematically, broadening the diet to include more options.

Since symptoms are under control, we can gradually go back to eating a wider variety of foods without causing discomfort.

What to Expect with a Functional Nutrition Program – My Process

The first step to working with me is to book a free 15-minute strategy call. This call is an informal chat about your health goals and how I can support you.

During our conversation, I’ll listen to your challenges and obstacles, and share how I may be able to help. 

Together, we’ll assemble a tailored package designed to meet your specific goals and needs and schedule your kick-off session. We may also initiate some advanced functional testing to pinpoint exactly what’s happening in your body.

At your kick-off session, we will conduct a thorough nutrition and lifestyle assessment.

We will identify the specific foods and stressors triggering your symptoms, making simple swaps to your diet using foods you enjoy that are also gut-friendly and meet your nutritional needs.

Simple lifestyle changes are discussed to boost your body’s natural digestive processes, targeting specific areas that are out of balance.

Over the course of our work together, we’ll follow the 5 R system to rebalance and restore your gut function, easing your symptoms, restoring more normal gut function, and broadening your dietary options.

Everything is personalized so that your body can accept the changes, even if you have a sensitive system.

I provide ongoing detailed nutritional analysis and specific feedback to ensure you’re getting enough key nutrients.

You’ll receive personalized, easy-to-prepare meal plans and recipes as needed to save you time and stress in the kitchen, along with strategies and tools for navigating the grocery store.

Our sessions are conducted securely over a telehealth platform, with email support between sessions to address any questions or concerns you may have along the way.

We also comb through into your history to identify factors that contributed to your issues and work to support underlying causes to prevent a recurrence.

By the end, you’ll have a clear understanding of how foods and stressors affect your digestive health.

And, we’ll have developed a personalized strategy to manage your symptoms, restore your gut health, and maintain those results long-term.

Functional NutritionTools

In my practice, I utilize a range of powerful tools tailored to each patient’s unique needs to support their journey to better gut health.

Therapeutic Diets

Therapeutic diets are designed to provide short-term relief from gut issues while we tackle the root causes (meaning, a restricted diet is not the end-all-be-all of your treatment plan!)

Once we’ve restored digestive health, it’s critical to expand the diet to include a wider variety of foods.

It’s important to me to help clients achieve lasting digestive wellness so they can enjoy a varied diet once again.

Therapeutic diets are customized to address specific gastrointestinal issues and may include the following (either solo or in combination):

  • Low FODMAP Diet
  • SIBO-Specific Diet
  • Elemental Diet
  • Gluten-Free Diet
  • Anti-inflammatory Diet
  • Low Histamine Diet
  • LEAP Diet
  • Bland Diet
  • GERD Diet
  • Autoimmune Protocol (AIP) Diet

Functional Nutrition Testing

To better understand each patient’s digestive health and tailor our nutrition and lifestyle recommendations accordingly, I incorporate specialized testing such as:

  • SIBO Breath Testing
  • Stool Digestive Testing (evaluating digestive enzymes, bile acids, and other markers to assess gut function)
  • Gut Microbiome Analysis (assessing the composition and diversity of gut bacteria)
  • Intestinal Inflammation Markers (assessing inflammation levels in the gut)
  • Nutritional Deficiency Testing (assessing levels of essential nutrients relevant to gut health)
  • Food Sensitivity Testing (Mediator Release Testing)

Therapeutic Supplements

While supplements can play a crucial role in gut healing, my approach is strategic and personalized.

I only recommend supplements when necessary to support specific areas of the body or to address nutritional deficiencies that cannot be met through diet alone.

I provide detailed recommendations with specific dosing instructions and incorporate supplements in phases, rather than overwhelming patients with a long list from day one.

Functional Nutrition FAQ’s

  1. How long are your packages? What is the duration of the program, and how often are sessions scheduled?
    • The duration of the program varies based on your individual needs, typically ranging from 6 weeks to 12 months, with sessions scheduled regularly, usually every 2 weeks.
  2. What is the cost of functional nutrition services? Are there payment plans offered?
    • Costs vary depending on the components and duration of the package, ranging from hundreds to thousands over our entire working period. Payment plans are available and decided upon during our free 15-minute consultation.
  3. Is functional nutrition covered by insurance? What are the payment options available?
    • Insurance coverage for functional nutrition varies but for the most part, it’s not covered well, so I am not contracted with any insurance companies. Superbills are available upon request so clients can submit to insurance for reimbursement.
  4. Can I still work with you if I have dietary restrictions or food allergies?
    • Absolutely, everything is personalized to accommodate your dietary restrictions and food allergies.
  5. How soon can I expect to see results with functional nutrition? What is the typical timeline for improvement in symptoms?
    • Results vary based on individual circumstances, but improvements in symptoms typically begin to show within a few weeks to a couple of months.
  6. Will I need to make drastic changes to my diet and lifestyle? How flexible is the approach to accommodate my preferences and habits?
    • No, the approach is flexible and personalized, focusing on sustainable changes that align with your preferences and habits.
  7. What kind of support do you offer between sessions? Can I reach out with questions or concerns outside of our scheduled appointments?
    • Yes, email support and quick calls between sessions are included to address any questions or concerns you may have.
  8. Can functional nutrition complement or work alongside the conventional medical treatments I’m currently receiving?
    • Yes, functional nutrition can complement conventional treatments, and we can coordinate with your healthcare team to ensure a comprehensive and integrative approach to your health.
  9. Do you work with clients remotely, or do sessions need to be conducted in person?
    • All sessions are conducted remotely via a secure telehealth platform, allowing for convenient access regardless of location.
  10. Can functional nutrition address conditions other than digestive issues, such as autoimmune diseases or hormonal imbalances?
    • Yes, functional nutrition can address a wide range of health conditions beyond digestive issues, including autoimmune diseases, hormonal imbalances, and more.

Ready to Take the Next Step?

If you’re ready to take charge of your digestive health journey, I invite you to book a free 15-minute strategy session with me. Let’s work together to create a personalized plan that supports your well-being.

Also, don’t forget to join our free Facebook community for expert tips, inspiration, and support on your path to digestive wellness.

Please don’t suffer for one more day when solutions are within reach. Take the first step towards vibrant health and vitality with me today.

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