There are multiple online databases that include full length documentaries.  

•  Kanopy collection includes a large documentary collection. You can browse all of them by clicking on "Browse" and then "Documentaries". 

• Films on Demand Contains over 30,000 educational films including in Allied Health, also includes documentaries. Browse by topic from the main menu.

• Alexander Street includes a few documentary features but primarily educational films in multiple disciplines. See all of them on their documentary channel here.