Are there treatment guidelines for bell's palsy?

Yes. Bell's palsy is an exclusionary diagnosis that first needs to be verified. Treatment is geared to maintain moisture of the cornea. Treatments range according to severity of disease. Possibilities include lubrication with drops or ointment, taping the eye shut while sleeping, temporarily sewing the eye closed, placing a weight in the upper lid to aid in closure. These are just to name a few....
It varies. Bell's palsy can vary widely between patients. It might me mild and short-lived facial weakness or permanent and complete facial paralysis. Treatment depends on the associated problems cause by the paralysis. To help guide treatment, other testing such as MRI scans or nerve testing might be needed.