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:
Why IBS is often a “label,” not a root cause
The research showing most IBS cases have identifiable, treatable drivers
How IBS can precede autoimmune disease by 5–10+ years
The role of intestinal permeability in autoimmunity
When IBS may actually be SIBO, celiac disease, IBD, enzyme dysfunction, or something else
The difference between IBS and IBD—and red flags you shouldn’t ignore
How nutrient deficiencies like zinc, glutamine, thiamine, carnitine, and magnesium impact digestion
Why fiber works for some people—and makes others worse
How polyphenols, fermented foods, and microbiome balance fit into healing
Medications that can contribute to constipation, diarrhea, or gut lining damage
Foundational gut practices that support digestion for everyone
Resources:
Izabella Wentz, PharmD
Website: https://thyroidpharmacist.com
Instagram: @izabellawentzpharmd
Facebook: Thyroid Lifestyle
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