Low back pain is a very common problem to have. Most cases are caused by muscle sprains or strains in the ligaments in the lower back (called a lumbar strain). These often occur after lifting something heavy. Other causes of low back pain include a slipped disc, spinal stenosis, and degenerative disc disease (among many others). None of these causes of low back pain are associated with diarrhea
. Diarrhea is most often caused by some dietary issue that you GI tract does not agree with or a GI infection. Sometimes diarrhea can cause severe pain, but this pain is most often located in your abdomen (not in your back). Thus, I would say that the two are unlikely to be related.
Both of these are problems that I think you should have looked at. Thus, I suggest that you schedule an appointment with your primary care physician
. He or she can examine your lower back and determine what the cause of your pain is. Most causes of low back pain do not require imaging to figure out. You can also discuss your bowel issues. Your doctor
will want to know how often you are having diarrhea and if there is any blood with it. I hope both of your issues get better soon.