Basic and clinical aspects of visceral sensation: transmission in the CNS.

Pain and discomfort are the leading cause for consultative visits to gastroenterologists. Acute pain should be considered a symptom of an underlying disease, thereby serving a physiologically important function. However, many patients experience chronic pain in the absence of potentially harmful stimuli or disorders, turning pain into the primary problem rather than a symptom. Vagal and spinal afferents both contribute to the sensory component of the gut-brain axis. Current evidence suggests that they convey different elements of the complex sensory experience. Spinal afferents play a key role in the discriminatory dimension, while vagal input primarily affects the strong emotional and autonomic reactions to noxious visceral stimuli. Drugs, surgical and non-pharmacological treatments can target these pathways and provide therapeutic options for patients with chronic visceral pain syndromes.