Diarrhea: Root Causes, Testing, and Treatment Strategies with Dr. Ilana Gurevich
Dr. Ben Weitz introduces the Rational Wellness Podcast episode on diarrhea and its complex differential diagnosis, featuring naturopathic gastroenterology specialist Dr. Ilana Gurevich. They discuss defining diarrhea using the Bristol Stool Chart and distinguishing acute from chronic cases, including when to investigate (about 4–5 days for new onset). Gurevich outlines an acute workup using LabCorp's rapid GI Pathogen Profile PCR stool test, notes limitations and false positives, and explains her approach to chronic diarrhea evaluation, including GI-MAP with optional bile acid testing (OMX), pancreatic elastase and steatocrit for fat malabsorption, and assessment for SIBO/SIFO and H. pylori (emphasizing conventional confirmation and virulence factors). They cover bile acid malabsorption and treatment with bile acid sequestrants and fibers, exocrine pancreatic insufficiency and enzyme dosing, microscopic colitis requiring diagnostic colonoscopy biopsies and budesonide, carbohydrate malabsorption breath testing, hydrogen sulfide SIBO uncertainty, the role of stress/nervous system and motility, and supplement causes like excess magnesium or vitamin C.
00:00 Podcast Intro
00:59 Why Diarrhea Is Complex
01:52 Meet Dr Gurevich
02:39 Acute Loose Stool Workup
03:07 Fast PCR Stool Panel
04:47 Treating Blastocystis
06:16 Defining Diarrhea
07:46 Acute vs Chronic Timeline
08:49 Food Triggers and EPI
10:18 Testing Limits and False Positives
11:03 Cholera PCR Story
13:56 GI Map and Bile Acids
15:45 Bile Biome Explained
18:25 Bloating Points to SIBO
18:54 Provoking Stool Tests
20:25 Biofilm Protocol Details
23:19 Large Bowel Dysbiosis Targets
24:24 Small Bowel Workup and H pylori
25:46 SIBO SIFO Testing
26:12 Organic Acids Debate
26:44 Pancreatic Enzymes Trial
28:19 PERT Dosing Basics
30:40 Bile Acid Diarrhea
33:46 Microscopic Colitis Clues
37:15 Treating Microscopic Colitis
39:28 Sugar Intolerance Breath Tests
40:02 Hydrogen Sulfide SIBO
43:55 Food Sensitivity Panel Critique
45:11 Nervous System Bucket
46:21 Motility And Transit
48:11 Wrap Up And Where To Find
Dr. Ilana Gurevich is a naturopathic physician, who specializes in gastroenterology. She's in Portland,
Oregon and she's the co-host of the excellent Turd Nerds podcast. She runs her practice out of
Dr. Ben Weitz is available for Functional Nutrition consultations specializing in Functional Gastrointestinal Disorders like IBS/SIBO and Reflux and also Cardiometabolic Risk Factors like elevated lipids, high blood sugar, and high blood pressure. Dr. Weitz has also successfully helped many patients with managing their weight and improving their athletic performance, as well as sports chiropractic work by calling his Santa Monica office 310-395-3111.
