Back to The Autoimmune Wellness Podcast
The Autoimmune Wellness Podcast

The Root Cause of IBS with Izabella Wentz, PharmD (Ep 071)

Mar 16, 2026 · 44 min · Ep 71

Episode 71: The Root Cause of IBS — Interview with Izabella Wentz, PharmD

What if IBS isn’t a true diagnosis—but a placeholder? What if bloating, cramping, urgency, constipation, diarrhea, and food reactions aren’t signs that your body is “too sensitive,” but clues that something specific and treatable is being missed?

In this episode of the Autoimmune Wellness Podcast, I’m joined by Dr. Izabella Wentz, integrative pharmacist, bestselling author, and longtime leader in the root-cause approach to chronic illness. Many of you know her work in the Hashimoto’s community—but her newest book turns that same investigative lens toward digestive health.

Izabella’s latest book, Finding and Treating the Root Cause of Irritable Bowel Syndrome, challenges the idea that IBS is a final answer. Instead, she reframes it as the beginning of a deeper investigation—one that considers bacterial overgrowth, enzyme deficiencies, nutrient depletion, intestinal permeability, medication side effects, food intolerances, thyroid dysfunction, and more.

This conversation is especially relevant for the autoimmune community. Many people who go on to develop autoimmune disease report years—sometimes even a decade—of digestive symptoms before receiving a diagnosis. We explore why that overlap exists, what IBS may be masking, and how improving gut health may shift the trajectory of long-term immune health.

In this episode, you’ll learn:
  1. Why IBS is often a “label,” not a root cause
  2. The research showing most IBS cases have identifiable, treatable drivers
  3. How IBS can precede autoimmune disease by 5–10+ years
  4. The role of intestinal permeability in autoimmunity
  5. When IBS may actually be SIBO, celiac disease, IBD, enzyme dysfunction, or something else
  6. The difference between IBS and IBD—and red flags you shouldn’t ignore
  7. How nutrient deficiencies like zinc, glutamine, thiamine, carnitine, and magnesium impact digestion
  8. Why fiber works for some people—and makes others worse
  9. How polyphenols, fermented foods, and microbiome balance fit into healing
  10. Medications that can contribute to constipation, diarrhea, or gut lining damage
  11. Foundational gut practices that support digestion for everyone

Resources:

Izabella Wentz, PharmD

  1. Website: https://thyroidpharmacist.com
  2. Instagram: @izabellawentzpharmd
  3. Facebook: Thyroid Lifestyle
  4. Podcast: Thyroid Pharmacist Healing Conversations

Book: Finding and Treating the Root Cause of Irritable Bowel Syndrome

Episode Timeline:

00:00 – Is IBS a diagnosis—or a placeholder?

01:34 – Introducing Izabella Wentz

03:38 – Why IBS is often a label, not a root cause

11:07 – When IBS is actually something else

14:01 – Food reactions: IBS vs autoimmune sensitivities

18:35 – Why IBS and autoimmunity overlap

20:10 – IBS vs IBD: knowing the difference

23:09 – Nutrient deficiencies and digestive dysfunction

28:40 – Fiber, fermented foods & polyphenols

32:56 – Medications that contribute to IBS

35:08 – Gut health foundations for everyone

38:12 – Wrap-up and closing

More from The Autoimmune Wellness Podcast