Symes has moved to the Pirelli Stadium until the end of the season while McDonald has joined the npower League Two promotion chasers on an initial month-long deal.
Symes joined Orient from Bournemouth in the summer, scoring twice in 18 appearances for Russell Slade's side.
McDonald featured twice for Burnley in August before spending the majority of the first half of the campaign on loan at Plymouth, playing against Burton in November.
- Sports & Recreation
- Russell Slade