Irritable bowel syndrome (IBS) is characterized by persistent or recurrent abdominal pain with altered bowel movement in the absence of a demonstrable pathology.IBS is one of the most common functional gastrointestinal disorders.However, the courses of IBS remain elusive.Hydrogen sulfide (H2S), a third gaseous modulator/mediator, has become recognized as an important endogenous molecular.H2S is synthesized from L-cysteine primarily via two endogenous enzymes: cystathionine-β-synthetase (CBS) and cystathionine-γ-lyase, and has been reported to be involved in nociceptive signaling and inflammation.However, the molecular and epigenetic mechanisms of CBS-H2S signaling in visceral nociceptive processing are not fully understood.