Current concept of pathophysiology and Biochemical factors involved in acute and chronic anal fissure

Anal fissure is one of the most common causes of severe anal pain. Factors which predispose people to develop anal fissure include diarrhea, constipation, childbirth, medication as well as constant saddle vibration (amongst professional mountain-bikers) and using a jet of water from a bidet-toilet. For many years, it has been generally accepted that a sphincterotomy, whether surgical or pharmacological, treats chronic anal fissure as it produces a reduction in anal pressure, reverses sphincter spasms and promotes fissure healing. However, recent studies cast doubt upon this explanation. A new theory explains that anal fissure healing depends on biochemical processes taking place in the anal passage. Eruption of tissues in the fissure region during defecation releases platelet products such as ADP, ATP, 5-HT, platelet activation factor, thrombin and substance P which cause the contraction of smooth muscles (of Internal Anal Sphincter and blood vessels) and results in difficulties in fissure healing. Reducing trauma of defecation by posterior perineal support plays an important role in anal fissure healing. It brings a significant improvement in the symptoms of patients with anal fissure