“We all experience situations in which our brains cause our bowels to go into overdrive. But in fact, messages departing the gut outnumber the opposing traffic on the order of about nine to one.” Michael D. Gershon, M.D.

Introduction

Published in 1998, The Second Brain by Michael Gershon addresses an important and neglected subject within the field biology, and which carries especial significance to medical theory and practice. This subject is the Enteric Nervous System (ENS) – the nervous system of the bowel – and the complex role that it plays in the body. In fact, the ENS displays a complexity of functioning akin to that of the brain—hence “the second brain”.
            Throughout the book, Gershon also reveals how the second (or “lower”) brain has been overshadowed by the first (or “higher”) brain within the science and medical professions, in matters of theory, research, and medical treatment; and his book represents a most substantial effort to redress the balance. Most significantly, Gershon highlights the fact that gut problems are routinely blamed on the brain; that is, on neuroticism of one kind or another—when it has for long been scientifically established that the gut itself – which is, “with respect to intestinal difficulties, right at ground zero” – perfectly capable of causing “enteric havoc” independently of the brain. Indeed, the independent functioning of the gut is stressed throughout this work, illustrated by references to scientific experiments and biological knowledge.
         Although Gershon – who was part-founder of the new medical field called neurogastroenterology – has effectively raised the scientific and medical profile of the enteric nervous system from underserved obscurity, his work still remains both highly relevant and insightful today with regards to the personal and medical implications of a malfunctioning gut.