Вы можете просто создать UINavigationController в методе, который отображает обратную сторону. Вот так:
- (IBAction)showInfo:(id)sender {
FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:@"FlipsideView" bundle:nil];
controller.delegate = self;
controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:controller];
UIBarButtonItem *doneButton = [[UIBarButtonItem alloc] initWithTitle:@"Done" style:UIBarButtonItemStyleBordered target:controller action:@selector(done:)];
controller.navigationItem.leftBarButtonItem = doneButton;
[self presentModalViewController:navController animated:YES];
[doneButton release];
[controller release];
[navController release];
}