My niece has fever that got as high as 104 but is gone now. has lost 7 lb. in last couple weeks. has had bouts of vomiting, darrhea, dehydration, and she has middle back pain, pain on the right side of her butt to leg and neck pain. The pain ranges from moderate to severe. Her sed rate is elevated. The Dr. and ER say not to kidney stones, gall bladder and appendicitis. What could it be?