anal fissure

Hello, My 36yr old son is suffering from anal fissures.
He had this before and when the cream didnt help he had botox injections under general anaisthetic. this worked but nw 2 years later its returned. The cream gives him an immediate headache. He is having warm baths twice a day, as suggested on some web sites, persissting with the cream but no joy, does anyone know of any healing ointment etc that might help, I wondered if calendula ointment used between the other cream applications or do you think this wrong.