Have you ever tried the anti-gas medications?  Sometimes gas can be very painful. 

I dont think its gas because I often have gas problems but thats usually fine especially when I can let it out. This feeling is like an intense ache that comes and goes in waves (mostly on than off though). I dont know any better way to describe it for my self than when you were younger and had a stomach bug or like a flew and your stomach felt off .. just the difference that almost all pain is in the back down towards my bum. I’ve already been at my local doctor just to see so it wasnt my kidneys but it wasnt….

Dang, I was hoping it was a simple thing.  I once had constant pain that moved around my chest and abdomen that I was convinced it was a big problem.   I went to the doctor and had all these scans (because I had colon cancer in the past) and they ended up telling me I had acid reflux. 

I have had intense lower back pain before but never for extended amounts of time, and usually it was associated with menstruation. I have had dull lower back pain from pouch inflammation, but it didn't persist for a long time or turn intense (knock on wood).

I bet someone on this forum has experienced what you're feeling and can give you some guidance, but in the mean time, I'd keep after the doctor until they help you figure out what it is, not just what it isn't, and provide you with relief.  That sounds miserable.  If you are taking pain medication for this, I have heard through this group that NSAIDs can increase or cause pouchitis, so it might be best to avoid those.