Can anyone help me with a problem i have?? its to do with abdomin & rectum pains nausea & being light headed..?

Lately i have been experiencing severe pains it comes and goes though. I get the pains all over my abdomin but sharp pain lower right side, i get severe nausea and start dry reatching and i feel real dizzy and light headed like i am gunna faint...then i get a sharp shooting up my rectum and then i need to go to the toliet and my bowels are really loose....the pain is really bad that i am in tears! :( (sorry for to much information but its horrible!) thank you to anyone who can help me and it is not possible to be a ual transmitted disease as i am not ually active... im 17 year old female.