Sounds like a hemorrhoid to me. You want to be sure you clean yourself after you have a bowel movement. Tuck's Hemorrhoidal pads are good for this. Also, Use Preparation H to ease the pain. Many times they come with a tip that you can use to apply the ointment inside of you. Make sure you put a little ointment on the outside of the tip by putting the tip on first and squeeze the ointment so that its coming out the top before inserting. It sounds worse than it is. That will ease your pain and make you much more comfortable that if you were to just apply it to the outside. Be sure to wash off the tip thoroughly when finished for next time. Hemorrhoids will make it painful to have a bowel movement. However, if is is so painful after keeping clean and using Preparation H, you will want to see a doctor. They can become very serious. You can still have a bowel movement, if you need to. But don't force or strain yourself. If you don't really have to have a bowel movement, don't push to have one. the Preparation H will help make it easier, but be sure to clean up with baby wipes or Tucks Hemorrhoid pads. You want to keep it clean.
Make sure you are eating right and drinking plenty of water. If you drink plenty of water, this will make your stool softer and it will be much less painful for you. When you have to strain and push, this is really when hemorrhoids are likely to happen.