blob columns and pdo

can anyone tell me if the IBM Informix PDO supports retrieving blob data?
the following does not work:

$stmt = $db->prepare("select pdf from docs where id=?");
$stmt->execute(array($_GET['id']));
$stmt->bindColumn(1, $pdf, PDO::PARAM_LOB);
$stmt->fetch(PDO::FETCH_BOUND);

header("Content-Type: application/pdf");
fpassthru($pdf);

I had to use LOTOFILE(...), really cruddy