Visceral pain

Visceral pain is pain that results from the activation of nociceptors of the thoracic, pelvic, or abdominal viscera (organs). Visceral structures are highly sensitive to distension (stretch), ischemia and inflammation, but relatively insensitive to other stimuli that normally evoke pain such as cutting or burning. Visceral pain is diffuse, difficult to localize and often referred to a distant, usually superficial, structure. It may be accompanied by symptoms such as nausea, vomiting, changes in vital signs as well as emotional manifestations. The pain may be described as sickening, deep, squeezing, and dull.^[1] Distinct structural lesions or biochemical abnormalities explain this type of pain in only a proportion of patients. These diseases are grouped under gastrointestinal neuromuscular diseases (GINMD). Others can experience occasional visceral pains, often very intense in nature, without any evidence of structural, biochemical or histolopathologic reason for such symptoms. These diseases are grouped under functional gastrointestinal disorders (FGID) and the pathophysiology and treatment can vary greatly from GINMD. The two major single entities among functional disorders of the gut are functional dyspepsia and irritable bowel syndrome.^[2]

Visceral hypersensitivity is hypersensitive visceral pain perception, which is commonly experienced by individuals with functional gastrointestinal disorders.^[3]