Problem of perianal abscess and fissure.

I found a lump near my left anus opening 15 days back. It pained very much during sitting, standing and during bowel movements. I consulted a doctor who said that its perianal abscess and medicines wont work and it has to be surgicaly removed. I consulted another doctor who gave me medicines stating its anal fissure. Now it has been 8 days that i have been taking Uniclav 625 and mobiceph (cephalexin and probenecid). I have been taking sitz bath thrice a day from last 10 days and applying Shield ointment as well.. Now from past 5 days there is no pain while standing or sitting or during bowel movement, the lump size has decreased but has not completly gone. Should i opt for surgery to remove it cmpletely or is there any chance with medicines . Kindly reply...i have been very much worried regarding this.