Having Back Pain For Long Time. Took Muscle Relaxers And Pain Medicines. Done With Physical Therapy. Suggestion?

Question: Hi, I have had back pain for about 7 years now. I am 24 male. The pain use to always be a light pain but has got worse over the years. The back pain is mostly lower but runs about half an inch along my spine up to the mid back. The pain is usually moderate but sometimes becomes Severe (maybe once every 3 months) for a couple weeks before it recedes back down to moderate. It relieves the pain when a lot of pressure is against my back in the spots with the most pain. I have went to a chiropractor which told me after two weeks that he would not be able to help if his treatment has made no difference thus far. He thought it was something to do with my digestive system. Then I saw a primary physician who just prescribed a couple types of muscle relaxers and pain medicines. Then after nothing work I was going to physical therapy which did not help. I had already been doing most of the exercises they were having me do. After considering what the Chiropractor said, I believe it may be my digestive system. When I have severe pain, I will have someone massage it or gently put their foot on me and put pressure while moving their foot around while I am laying down. Later on them days, It seems that I always have a bowel movement and I notice a slight relief in my pain. Any ideas of what this could be?

Also, at times around my tail-bone hurts and I have a discomfort in my hips. I do not know if this has any relation to my back pain.