Night time bed wetting or incontinence could be due to stress, functionally small bladder, diabetes mellitus, diabetes insipidus,
urinary bladder wall instability, UTI, stones and neurological problems.
Urinary bladder wall problem has been deducted in your case. However you can discuss your case with your urologist. The enumerated the possibilities can be investigated or ruled out one by one by your physician. A psychological assessment of the situation may also help.
Hope this helps.