Occasionally the epidural does not work, for whatever reason. You may have the option of undergoing another epidural procedure. For many women this works well, for others it is eitehr not an option or simply doesn't work. If you fall into this category, you will need a back up plan.
Many women will try to use other medications, like IV pain medications to help them with the pain of labor.
This may be a time where your doula and other support people can also help you with non-medicinal forms of pain relief, including positioning, massage, relaxation and more.