Demi Lovato has revealed what life was like in rehab as she battled emotional and personal problems.

The singer has previously endured a number of issues such as eating disorders and self-harm and in 2010 she was admitted to a rehabilitation facility.

Speaking to US TV's Katie Couric, Lovato said that she initially felt the clinic was like a "prison", with a number of rules in place.

The X Factor USA judge added that she wasn't allowed to use the bathroom by herself so that people could keep an eye on her. She said:

"Treatment was so difficult at first. I remember walking around saying, 'I'm in prison!' They needed to have those strict rules in order for me to understand how sick I was. I wasn't allowed to use the bathroom by myself, you had specific phone times. You're not allowed to have certain hair products that you could injure yourself with or possibly drink."

Lovato continued: "You were stripped of a lot of things. I also had somebody watching over me every single time I ate and if I didn't finish what was on my plate, and often [there were] times I would cry because I physically couldn't stomach it, and if that happened, I would have to have little consequences, nothing horrible, just like not being able to go to the cafeteria to eat [with everyone else]."