How should I repair my toilet sub floor joist?

I have a bathroom with water damage from a toilet that was leaking. Now that I have removed the tile, sub floor and wood floor, I found a floor joist underneath that has water damage and believe it should be repaired / reinforced. The dilemma is the lack of clearance on both sides of the joist - drain pluming for the toilet on one side and the water feed and air duct work on the other making it almost impossible to attach the reinforcements. Will the toilet position just have to modified after the reinforcements are established? The toilet would have to sit out 4-5 inches from the wall which may look a little strange. I also have water source and electrical wiring going through the joist. A very busy area. Any ideas?