Mischa Barton was all smiles as she left a New York party on Sunday night - despite having apparently sat in a puddle.

After telling reporters she was “feeling great”, the former OC star turned to get into her car, revealing a big wet patch on her rear.

The party was Mischa's first night out on the town after her mysterious hospitalisation nearly two weeks ago.

Her rep has so far refused to expand on the undisclosed “medical problem” that reportedly landed her in a psychiatric ward at Cedars-Sinai medical centre in Los Angeles on July 22.

According to onlookers, Mischa stuck to water and relaxed on a couch at Sunday's bash at the Cooper Union Hotel, before calling it a night and heading home just before 11pm.

Mischa at Paris Fashion Week earlier this year