Would an mri of lumbar w/o contrast show cause of inten low back pain, loss of blder control, numb low abdomn that touch sends strong ting. down legs?

It is possible: but with the symptoms you describe you need to be evaluated immediately by a physician to rule out a correctable problem before it is permanent.

Here are some ...: Imaging study with MRI is intended to show if there is anatomical structural "abnormality" which is rare in the young except ones with congenital or post-traumatic change. However, the degree of structural change is not always linearly proportional with functional changes, but at times disproportional. In your condition, it's likely in such condition or with some sort of neuropathy. More? Ask Doc.