Please Help Me Out With These Symptoms

Hii.. Well im a 19 yr old girl and ive always seemed to have probs with my digestive/ stomach area. Gross, I know lol but startin like 3 yrs ago once in a while I would have really bad constipation like once I had to go to emergency room cause it was like a week n a half and I was feelin so sick I had to get enema. Also I tend to get very bloated with so many foods, its so uncomfortable. Actualy like 2 yrs ago I figured out I was lactose intolarent so I tend to stay away from all dairy food or I take lactaid with it. But like starting last week I just have these like dull, achy cramps and sometimes I goes a little to my lower back. It seems to get worse at night and feels better when I do exercise and stuff. Could my history and all this be symptoms of ibs? The pain is just constant...Its not like severe but sometimes the ones in my lower back feel like menstrual cramps.. What do u think this could be..I usually need to lie on my stomach at night or something..Please help. Im away at college and scared cause im a bit of a worrier.Thanks