Pain in lumbar region. Movement happens.

I have severe pain in lumbar region. exactly in the middle point where the curve is, near the spine. this pain is there from many years, and there is mass accumulated, around that area. the mass which is accumulated in that lumbar region is from long years, i am obese to height, that part of the fat is not going even if the other parts of the fat is gone. I have a history of IBD, there is inflammation in the GI tract, which is diagnosed recently and treatment is been started, well this issue was there from a long time, which was not correctly diagnosed all these time. As I have constipation due to IBD, whenever motion doesnt happen i get very shooting pain in that region, especially in the middle point. and it even stretches down. when the bowel movement happens. the pain is relieved. But now a days, even if the motion happens I have a sever pain in that point. and cannot walk,. I feel it also effects my mind. I become blank, cant think properly, feel very tired.