Book Review: Second Edition of "Natural Approach to Gastroenterology" by Eric Yarnell, ND

The first edition of Eric Yarnell, ND’s textbook Naturopathic Gastroenterology, published in 2000 was an enormously valuable contribution to naturopathic education. The newly released second edition, now titled Natural Approach to Gastroenterology, also by Yarnell, is a major step forward not only for naturopathic education, but for the field of gastroenterology and the healthcare profession as a whole. Yarnell’s book has been marketed as a resource for both the student and the busy clinician. Although it is first and foremost a textbook, this review will focus on its clinical utility.

Although it speaks more directly to students (more on that below), Natural Approach to Gastroenterology is a worthwhile investment for clinicians as well. The main text is divided into 13 sections, 9 of which concern regions or organs (eg, esophagus, stomach, liver). The remaining 4 sections are devoted to “General Information,” “Gastrointestinal Infections,” “Miscellaneous,” and “Forms and Questionnaires.”

Naturopathic doctors treat the digestive system as a means to heal far more than digestive symptoms. The “General Information” chapters explain the rationale for that and provide a survey of historical precedent and scientific research in support of systemic toxemia, leaky gut, probiotics, intestinal immunity, and the enteric nervous system. This is essential information for any naturopathic student or health professional interested in understanding, for example, the physiologic mechanism behind treating joint aches by optimizing digestive function. The last chapter in this section is on diagnosis and offers a practical review, particularly for management of acute cases. In the first edition of this book the “General Information” section also included a materia medica of common botanical, homeopathic, and nutrient therapies; in this version that information is redistributed throughout the text to align with the most relevant organs or regions. All information, references, and tables regarding homeopathy are eliminated from the second edition, with exception of single reference to homeopathic drainage remedies. Yarnell’s text is dominated by physiologic medicine, with only occasional references to energetic medicine like acupuncture and stress reduction.

The section on the liver has been extensively developed in this edition, including a marvelous chapter on metabolic liver disease and more useful, detailed information on hepatoprotective agents and liver restoratives. The cholagogues and choleretics in the gallbladder section are similarly updated. Both of these monograph chapters have cross-reference tables, improving the text’s functionality over the first edition. Another advantage of the second edition is the inclusion of several algorithms; “Natural Approach to IBS,” “Diagnosis and Management of Celiac Disease,” and “Natural Approach to Diarrhea” are standouts. In fact, the whole chapter on diarrhea is a excellent; if you lack confidence at all in managing acute diarrhea, you can solve that problem in 30 pages. Similarly the chapter on treating parasites is better organized than the earlier edition and is a good go-to resource. The chapters not to miss in the colon section are the IBS chapter, which includes natural treatments for each subtype; the comprehensive chapter on ulcerative colitis; and the very brief chapter on colonoscopy preparation.

Volume II begins with a section on the small intestine.

The much-expanded Crohns disease chapter alone is worth the shelf space and cost of the book.

The much-expanded Crohn’s disease chapter alone is worth the shelf space and cost of the book. You could read this chapter 3 times and be well on your way to becoming a Crohn’s specialist. The chapter on gastroesophageal reflux disease (GERD) is a close second for most thorough and, given the frequency of patient presentation, is a strong contender for most useful. The information in the stomach section is invaluable—especially the chapters on hypochlorhydria, Helicobacter pylori, and the herbal bitters. However, the information is spread out, so it’s worth taking the time to read through it all and consolidate the information into a chart of your own.

The 2 final sections are “Miscellaneous” and “Forms and Questionnaires.” The former includes a new chapter on bariatric surgery. The latter is a convenient compilation of standardized forms referred to throughout the text to gauge severity and monitor subjective experience of various named pathologies. These forms are also useful for outcome studies.

To further illustrate the utility of Natural Approach to Gastroenterology, here are 7 changes I immediately employed in my practice the week I read the book:

1. Added Anti-Saccharomyces cerevisiae antibodies (ASCA) to my inflammatory bowel disease panel. Revamped my celiac panel and added reflex tests.
2. Added 2 brands to my probiotics handout and included the recommendation to refrigerate all probiotics, regardless of recommendation on label.
3. Sent Bifido species to my family in Japan for radiation sickness.
4. Added Fumaria to a GERD patient’s protocol to improve lower esophageal sphincter (LES) tone.
5. Added to my oral contraceptive pill (OCP) support handout the fact that pathogenic bacteria can convert to cholesterol to estrogen.
6. Used elimination challenge flowchart as a teaching tool.
7. Resolved to ask the gastroenterologist about safer colonoscopy preparation.

In addition to the material of obvious clinical utility, there is also much in this text that is impractical for daily clinical practice but illustrative for students—for example, the historical context of the toxemia hypothesis, coverage of research studies on products not available in the market, discussions of botanical medicines occasionally without dose or form, and musings as to whether Darwin was lactose intolerant. Yarnell’s writing style is clear, direct, and very satisfying to read, and I think most of us would like to indulge our inner naturopathic science nerd and read it cover to cover.

However, if you do not have that luxury of time, the following table summarizes the highlights mentioned in this article and will help you “trick out” your copy for use as a clinical handbook.