Reviewing the Peripheral and Central Mechanisms of Visceral Hypersensitivity in Intestinal Disorders

Visceral hypersensitivity (VH) is a condition where the internal organs have an enhanced sensitization to normal physiological stimuli or mild pathological stimuli, leading to chronic visceral pain or other discomforts, which is a typical characteristic of some intestinal disorders, such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). VH might be caused by gene, psychological disorders, social stress factors, gut microbiota, and some other factors, but the exact mechanisms are not yet clear. This review focuses on recent developments in the effect of intestinal cells on sensitization of nociceptors, high excitability of brain nuclei regulating visceral pain, and the novel roles of gut microbiota in VH. It is hoped to synthesize research advancements to demonstrate the possible peripheral and intracerebral processes of hypersensitization. Additionally, more animal experiments and clinical studies are still needed to improve our understanding about VH to reduce the suffering of patients with IBS and IBD.