How Can Recurrent Sciatic Nerve Pain In The Leg Be Treated?

I hurt my back and few months ago and have sciatic nerve pain down my left leg, I have had 2 epideral injections and done physical thearpy but everytime after thearpy I have to go the bathroom and have extremley loose stools after about 24 hours it goes away. Only happend after thearpy or if I have walked or rode a stationary bike for a little while then it starts up again but my sciatic pain is worse now but Im not in the bathroom all day either and not getting thearpy.