It was a hematoma that developed. A new fistula has very fragile walls, and sometimes it can bleed very quickly into the tissues. It is very painful. Rubbing it will not ease the pain. We do ice 20 mins on/20 mins off for first 24 hours, then heat is recommended after that. Some patients prefer ice after 24 hours because it feels better. It can take several weeks for it to resolve. I would question if this fistula was really mature enough to be stuck, or maybe this Nurse didn't have good skills to stick. We have people designated as "master stickers" to cannulate the first few times until it is more developed.