Reverse proxy - retry connection in response to error 50x

I have a reverse proxy setup pointing to a single IIS server. On occasion, the backend IIS server throws a 500 that is easily resolvable by a browser refresh. Our developers are having trouble figuring out the actual cause of the 500, so I'd like to come up with a work-around.

I've read some posts about load balancing where it sounds like this should be possible, however my scenario has only one backend server rather than multiple.

Is there a way to have nginx automatically retry after receiving a 50x response?