Assuming you are using symfony 2.0.x :
You should not bind your request before sending data to the view, neither render the view before testing for submitted data (I guess you show us test code)
public function editAction()
{
$id = 5;
$em = $this->getDoctrine()->getEntityManager();
$request = $this->get('request');
$entity = $em->getRepository('SurgeryPatientBundle:Patients')->find($id);
$form = $this->createForm(new \Surgery\PatientBundle\Form\PatientsType(), $entity);
if ($request->getMethod() == 'POST') {
$form->bindRequest($request);
if ($form->isValid()) {
return $this->redirect($this->generateUrl('task_success'));
}
}
return $this->render('SurgeryPatientBundle:Patient:newpatient.html.twig',array('form'=>$form->createView()));
}