Anal fissures are tears in the lining of the anus or anal canal. It is an acute condition, symptoms of which may include painful bowel movements, bloody stools, a visible tear in the anus, and bad smelling discharge. 

While usually an acute condition, it may be considered chronic if symptoms last for more than six weeks. Anal fissures may also be a symptoms of another condition, such as Crohn’s disease or ulcerative colitis. 

Drug classes often used to treat anal fissures include vasodilator nitrates, topical calcium channel blockers, and botox.