Tapping, throbbing in anus

I get that sometimes too, most usually after being constipated and having to strain a lot to get something out (although sitting on the toilet too much due to diarrhea can also cause it to happen).

I know that I have internal hemmroids, and as they are very common, you probably have them as well; I think that's what gets to throbbing when they swell.

That is a hemmroid I have the same thing it swells up after you take a dump and then after a few hours it goes down some. If yours is sticking out all the time then you proababy should see a doctor as it can be removed, but everyone says the pain is very bad. I know someone that got the bands done that is where they use rubber bands and cut the blood off they shrink up and die or somthing he was off work for 2 weeks and then he sat on a donut at work had to put cream on it all the time. He says it worked I haven't looked into it because mine only bother me after I go to the bathroom and they go back inside. hemmroids happen for all kinds of reasons some say its being over weight but the guy at work was thin as a rail so its just defect I guess. I would have it checked out because I know a friend his wifes boss's wife had a bump like that she was pregnant she thought it was hemmroids also but it turned out to be rectal cancer she had to go on a colostmy bag. I think they removed her anus and parts of her rectal area. She was only 38 years old. So get it checked out by a GI doc not a regular doctor.