I have been having burning sensation above the anus and in the lower aspect of the buttocks on both sides for 4 months . no reddness the skin looks completely normal.what could it be?

Focal anal pain: Could you be referring to fissures, fistula, abscess? Sexually transmitted disease (syphilis, gc, hiv, etc.) should be considered. Hemorrhoids & rectal prolapse can appear as a painful swelling. Anal trauma of any kind may cause mechanical injury. Skin eruptions need to be considered. But if fissure is confirmed, topical Nitroglycerin is traditionally used, although other agents can be compounded.