Jeff 'The Dude' Dowd SUING UCLA -- 'Lebowski' Inspiration: Docs Killed My Mom

Hollywood producer Jeff Dowd -- who inspired "The Dude" character in "The Big Lebowski" -- is suing UCLA's hospital for $10 million ... saying his mom died because of poor communication between doctors, TMZ has learned.

According to the lawsuit ... Dowd's elderly mother was hospitalized March 29, 2013 suffering from bronchitis ... and was dead within a month after she got progressively worse -- suffering internal bleeding, dehydration and finally a massive stroke.

Dowd tells TMZ ... his mother was handed off from one doctor to another, often without adequate information about what meds she was taking. Dowd says it was that breakdown in communication that led to her death.

Dowd -- who's also suing a convalescent home -- says he wants to help reform communications in the medical field ... saying hundreds of thousands of people die in hospitals every year from that kind of failure.

And that ... the Dude does NOT abide.