Demi Lovato is to open up about her stint in rehab in a new documentary.

The Camp Rock star - who sought treatment in 2010 as she was battling bulimia and bipolar disorder - told Access Hollywood she hopes telling her story in MTV show Demi Lovato: Stay Strong will help others.

"I think I've definitely had my rock bottom and I think that was probably right before I went into treatment where I said, 'I definitely need help'," said the starlet.

The 19-year-old continued: "I think it was really important for me to do because I feel like I've been given an opportunity to speak out on issues that are really relevant in teenagers' lives today,

"So I feel like being open and honest with my fans about the things I've been through could possibly help them."

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