What can be done for an anal fissure after two operation of anal dilatation?

Sphincterotomy. After less invasive approaches fail (such as dilation and medication), a lateral sphincterotomy (cutting of the internal anal sphincter) can be performed to help heal the fissure.
New physician . That is an older treatment, newer and better ones are available. See a new physician. You have some of the more famous colorectal surgeons in the world in chicago - i would suggest your see them. Look up abcarian - you can't go wrong with him. Older guy, probably close to retirement, but he knows this stuff very very very well.