What Causes Bloating And Lower Back Pain With Severe Constipation?

Help. Extreme problems with defecation sudden onset 8/24/13 and cannot get a diagnosis. Extreme bloating - low back pain very painful at times and need for laxative is not even enough. Feels like obstruction can t find doctor to diagnosis - sent for physical therapy. Left renal fullness on two sono in late 2013, disc bulges, rectocele since repaired. Need help getting accurate diagnosis