<s>[INST] I m having a lot of low back pain and leg pain so badly that I am having trouble sleeping. It comes and goes so I assume it is just normal aging back pain or a herniated disk. But now a new seemly unrelated system has developed. I have diareha for the last five days. I started tthiking the two are related. what do you think? should I be concerned? [/INST] diarrhea is usually not related to back ache ... treat the diarrhea  and back ache separately! but sometimes severe diarrhea can lead to back ache due to excessive straining or explosive diarrhea! </s>