Severe lower abdomen pain and lower butt pain after bowel movement?

Hemorrhoids likely.: This is likely due to hemorrhoids. The history strongly suggest it, since pain is after a bowel movement, and likely associated with straining. It could be anal fissure, or possibly another colon/anal issue. Depending on your age, and if this has been going on a while, you might want to see your doctor to get a rectal exam/testing to make sure it is not worse, like cancer, etc..