Hi, lump at anal canal may be due to a perianal abscess and this generally pains. Other causes are of external hemorrhoids with doesn't cause pain but occasionally when get thrombosed causes pain. A skin tag formation secondary to fissure in ano also presents same but that pains. Kindly get evaluated physically. You may require a short scopy done to rule out above problems. Feel free to ask any further quary related to your problem. Regards.