You might want to ask your Orthopeadic about Femoral Impingment. This is a very undiagnosed problem that results in hip pain, sometimes in the butt. Effectively the head of the femur is ever so slightly misshaped (not visible on a standard x-ray) and over time as it 'hits' the acetabular it will finally tear the labrum. The excercises you described will have agravated such a condition. Have a look at the following link for more information.
It can be very effectively treated with either an arthroscopy or hip surgery.