About a month ago I experienced diarrhea for about a week and mucus in my stool. I also discovered a small lump that felt like it was just inside my anus, although there was no discoloration. Everything seemed to go back to normal although the lump remained after going down, slightly. It was also no longer painful. Today there was bright red blood in my stool and if I press on the lump more blood would come. What could this be?