Colitis??

So I was in a unreal amount of pain starting last Thursday, Friday is even worse and by Saturday it was unbearable.. I felt like my stomach was trying to come out of my skin, my back was in knots, throwing up, diarrhea and then all of a sudden I went to the bathroom, to go pee (and sense I had diarrhea, I went #2 too...) when I wiped I noticed blood... And then I looked in the toliet and it was full of blood sooo I was rushed to the ER.. And in all gods honesty I thought I had a miscarriage (I was due for my period the next day, so wasn't sure!) get there and find out I have Colitis... What is this??? The hospital was so hectic and I was so doped up I can't remember much about what they said about it... Has anyone ever had it?? Can I get it again?? It's been a week and I'm still feeling the back aches, stomach turning stuff..