bleeding diaper rash

My baby has always had gas problems from the day he was born. We, after his first week, had to switch to formula and the last couple days hes been in so much pain. Crying and holding his breath until he turns red to push it out. Recently, with every fart, hes been "sharting" himself with poop that is a solid, gritty yellow color. Yesterday he started having a diaper rash and i noticed when changing him that his bottom was bleeding pretty bad. Has anyone else experienced this? I feel like I should take him in his doctors soon.