The enteric nervous system is a specific part of the autonomic nervous system, whose role is mainly concerned with ensuring the proper functioning of the gastrointestinal tract. Numerous scientific studies show that the enteric nervous system plays many roles: it is responsible for peristalsis of the gastrointestinal tract, controls gastric acid secretion, regulates fluid permeation through the lining epithelium, controls local blood flow, and interacts with the immune and endocrine systems of the gut. Enteric nervous system failure or dysfunction can cause a number of intestinal neuropathies. These can be congenital or acquired neuropathies including those accompanying other conditions such as gastroparesis, achalasia, Crohn’s disease, Chagas disease and many others, including neurodegenerative diseases. This article is a review of the literature and provides a comprehensive study of the enteric nervous system in normal conditions and numerous clinical conditions.