My husband has been taking diclofenaco for pain he gets in his leg. It works for a while but pain keeps coming back! Is there a better med he can take?

Piroxicam. Voltaren (diclofenac) doesn't last extremely long. It usually is dosed more frequently than once per day. Longer lasting nsaids can include both Aleve (naproxen) and Piroxicam (aleve (naproxen) is otc and Piroxicam is a prescription).
See his doc. If diclofenac (which is a powerful nsaid) isn't effectively treating your husband's pain, then you need to chat with his doc about either increasing the dosage or switching to a different medication. The choice of medication will depend on the cause of his pain and how he responds to pain meds. Definitely need to see his doc for this one.