Severe constant stomach cramps

I'm desperately seeking clues about what can be wrong with my 16 year old daughter. For the last two months, she has been experiencing extreme, constant stomach cramping, severe constant headaches, and a constant rectal pain, especially severe during/after defecation. We've seen a number of gastroenterologists, a neurologist, a rheumatologist, a rectal specialist, and general practitioners but none have an idea about what is wrong.

In the past 5 days, we have noticed the cramping is getting progressively worse. She wanted to avoid using Vicodin (causes constipation) earlier but now needs it daily due to the intense pain. She has been taking Miralax to help with bowel movements. She is basically bed ridden now. She has insomnia but interestingly when she eventually does fall asleep she can sleep for 8 or more hours (the pain does not seem to wake her).

She has taken just about every imaginable test and all have been negative at this point. She did have a brain MRI that showed a small white spot in the temporal lobe that could cause abdominal seizures but her stomach cramping is constant and the neurologist didn't think that was the problem.

Her current symptoms:

%u2022 Severe, constant stomach cramping in a circle around the navel. Now it hurts to even move.
%u2022 Severe, constant headache
%u2022 Constant rectal sensitivity and pain but severe during/after defecation (no roids or fissures diagnosed). Using topical lidocaine for pain
%u2022 Constipation
%u2022 Extreme difficulty defecating but this may be due to a stretched colon from severe constipation
%u2022 Bloating (we went through a cleanse a few days ago and after she was cleaned out her stomach was still bloated, hard and distended. MRIs have shown her stomach and colon filled with air as if she's swallowing air. Her stomach makes tremendous noises at times.
%u2022 Area where stomach cramping occurs is very sensitive to the touch
%u2022 Insomnia has increased in last two months
%u2022 Occasional tingling in extremities, arms and legs fall asleep too easily
%u2022 Recent (within the last week) sensitivity to light
%u2022 Recent sensitivity to motion (e.g., car sickness, never had that before)
%u2022 Has had dimmed vision about 2 - 3 times per month where she practically blacks out temporarily. Not necessarily related to standing up suddenly.
%u2022 Sustained colonus (after meeting with the neurologist this does not seem to be related but we have a few more neurological tests to confirm)
%u2022 She seems to have an itch in her throat and has to clear it to satisfy the itch.
%u2022 Painless swelling at the base of her back (started about 3 weeks ago, doctors have no idea)

Thanks.