I have had back pain for 7 years, and learned to cope with it. For the past three days I have had severe back pain, mostly lower and neck area and abdominal pain as if I had diaharria, my stool comes out mucus and tissue like. I recently had some soft stool.
Back pain and abdominal pain may be of different origin, or may be of part of same disease like satiation syn Chat Doctor.  Complete bed rest for a certain period of time is the initial mode of treatment in low back pain. Pain can be controlled by medication, exercise, weight reduction, lifestyle modification etc. And if the condition is not improving and impairing your activities of daily living then you have options like epidural injection and ultimately surgery. Take paracetamol 1 gm twice or thrice daily as required initially for some days.