I Have A Spasm And Backpain For About Two Months

I have a spasm and backpain for about two months . I have checked by MRI for disc prolapse but there was no. Just a pressure on sciatica . During acute attack I am sufffering from GIT disturbance,diahorhea, increase temperature, feel very cold, increased urination, feel thirst, lethergy and malaise and bitter mouth taste in addition to backpain. Can I know what diagnosis and treatment are for this, please.
MANY THANKS