What Causes A Painful Spot In The Anus?

In the past week, I been having some anal pain. Most of the time it is will sitting. It doesn't hurt while having a bowl movement. I have had blood spotting in the past. Not on a regular basis. I thought it might be a Hemorrhoid. Today I noticed there is an internal spot about 1/2" tinside that is the size of a BB. When this spot is touched, that is when there is pain. I bought some Hemorrhoidal Ointment today, do you this this may help?