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A painful bump which is red and almost 2 inches away from anus about the size of a pea which has grown in the past day or so ... seems more likely a boil or infection of the hair root.It should be treated with antibiotics and may also need drainage.
It needs physical evaluation to confirm it.
I will suggest you to see a local physician to get physical evaluation as it is not possible to do so over the net and get it treated according to the findings.
Meanwhile, please do not apply hot compresses because if it is infection, it will grow more fast. Just take motrin or alleve for the time being till you see a local physician.