Constant lower abdominal pain and severe bloating... Please advise!

About three weeks ago I started noticing bloating, constipation, and lower abdominal pain. It got worse and worse as the days went on. I went to the walk-in clinic were they took x-rays to determine if there was an obstruction, which there was not. The only thing the x- ray showed was a moderate amount of feces. They told me it was just constipation and suggested Miralax. I took Miralax for five days with no results and went back were they performed a fleet enema on me... I did get relief but the abdominal pain got worse.
Again I went to the doctor because the pain was so intense. My entire lower abdomen feels sore and tender with a constant ache on my left side. Sometimes I get shooting pains on my lower left and lower right side. These pains travel to my lower back and a couple times my leg hurts!
The doctor gave me a pelvic exam, tested my urine and blood to rule out other things besides intestinal. Not a thing was found... I went to a gastroenterologist the next day and she thought it was IBS and prescribed me Amitiza and Bentyl. I have been on the Amitiza and it makes me have frequent watery BMs...and the Bentyl does not do much.
The pain is constant and I feel like I'm pregnant I'm so bloated (I'm not!) could this really just be IBS? Could the pain be reproductive (i.e. ovarian cysts)
I'm going to school for nursing and it is really interfering with my education... I really could use some insight!! :( Nothing I try seems to alleviate the pain. I drink lots of fluids, eat bland food in small portions,  no caffeine or alcohol, use hot compresses, the list goes on. Please help?

[Lionna]

Have you tried changing your diet? try a gluten free diet for a week and see how you feel. more fruits and vegies, lean proteins and walk everyday, take out white, processed foods.You could also have stress and it is effecting you through your stomach, (are you a capricorn?)  hope you feel better!

[Caryopteris]

I think you should see a gynecologist for ovarian ultrasound too, since that can cause bloating.