Chaos Inside UCLA

Sources inside UCLA Medical Center tell TMZ Britney checked into the facility using an alias. We will not divulge the name, but what happened inside is bizarre.

Our sources say Britney said she was on Adderall, a stimulant used to treat Attention Deficit Disorder, and was taking up to ten laxatives a day. Side note -- cameras caught Spears a few days ago picking up a bagful of laxatives.

We're also told, when she was admitted, Britney accused her mom of "sleeping with my boyfriend." She wasn't specific on who she was referring to.

We're also told that for a time she was hurling profanities at her parents and staff.