Not really sure if that is IBS or not. My 23 year old sister was just diagnosed with IBS as well she has had this ongoing for a year and a half (the whole time she was in Iraq) her symptoms are bloating, bleeding instead of a bowel movement, constant cramping, and when she tries to do a bowel movement she can be on the toilet for an hour and nothing happens. She is on a very strict diet...NO dairy, NO soda, NO red meat....basically she eats salads, drinks capri sun(the only thing that doesn't kill her stomach),lots of fruits and veggies...hopefully you find out if that is definitely what is wrong, and hope this helps a little..
Not sure it is IBS 
