Ray J crashed and burned the morning after the Billboard Music Awards ... and landed in the hospital ... TMZ has learned.

We're told Ray J was extremely upset after his confrontation with Whitney Houston's family -- notably Pat Houston -- during the awards ceremony. On Monday morning, someone went into Ray J's hotel room and realized the singer was "out of it" and couldn't get out of bed.

We're told Ray J was extremely disoriented and was immediately taken to the hospital by ambulance.

As for what happened ... it's looking like a combo of exhaustion and dehydration. Ray J had just returned from a quick, 32-hour round trip to China for business and when he landed he immediately drove 4 hours to Las Vegas for the awards show.

Ray J is still in the hospital. No word on when he'll be released.

It's the most famous crash diet in history ... the Master Cleanse ... but according to celebrity super-trainer Jillian Michaels ... it's dangerous for your body.

Michaels was out in Malibu this weekend, when we asked about rumors that Beyonce dropped the baby weight by going on a Master Cleanse ... a 10-day program where people are only allowed to consume tea and lemonade mixed with maple syrup and cayenne pepper.

"Don't do the Master Cleanse," Michaels told us bluntly ... "It's bad for you."

Back in 2006, Beyonce told Oprah she shed a TON of poundage by using the program for 14 days ... but now, Michaels insinuates Beyonce is more educated about the dangers of the Cleanse ... and HIGHLY DOUBTS the singer would ever do it again.

But fear not ... Michaels DID offer some healthy weight-loss advice that's sure to work every time ... so watch the clip ... and then get off your ass and work out.

A rep for Al Jarreau tells TMZ he was diagnosed with pneumonia before the concert, saying, "Mr. Jarreau believes that his illness and fatigue resulted from a very busy week on tour, which included 4 concerts in Austria. He will spend a short time recovering at home before resuming his normal work schedule.

Legendary singer Al Jarreau canceled a concert this evening in Escondido, CA ... TMZ has learned. 

Jarreau was scheduled to perform at The Centre at Lexus Escondido, but the concert hall said Jarreau would not be performing because he was ill. A source close to the situation told TMZ he was taken to the hospital, but the concert hall would not confirm.

The entire concert was not canceled -- George Duke, who is also on the bill, will still perform.

Jarreau, who is 72, has won 6 Grammys ... including one as recent as 2007... and nominated for 12 more. 

Calls to Jarreau's rep were not returned.

Former wrestling superster Chyna collapsed at a porn convention in Miami today and was taken to a nearby hospital ... TMZ has learned ... her third such episode in as many days. 

Chyna was appearing at the 2012 Exxxotica Expo to help promote Vivid Entertainment's porn parody of "Avengers" -- she plays She-Hulk (yes, really). A rep for Vivid tells TMZ the company was worried about her after yesterday's medical scare ... but Chyna insisted she was ok. 

We're told Chyna made it to the convention center today, but passed out in the lobby and was taken to Mt. Sinai Medical Center in Miami Beach.

As TMZ first reported, in addition to passing out yesterday at the convention ... she was kicked out of a party on Thursday night for her unruly behavior, which included passing out in a pool. 

Former wrestling superstar Chyna collapsed in front of the main stage at a XXX convention in Miami moments ago ... TMZ has learned.

Sources at the scene tell us ... Chyna was hanging out at the 2012 Exxxotica Expo when she suddenly dropped to floor.

We're told several people rushed over to help ... and carried Chyna out of the expo and into a nearby hotel where she's now resting.


Sources say Chyna was checked out by paramedics at the scene -- who didn't feel the porn star needed to be hospitalized.

We reached out to Chyna -- so far, no word back ... but we do know she's canceled a Friday afternoon appearance at the XBiz Summit -- another porn convention.

Phillip Phillips -- one of the finalists on "American Idol" -- has been URGED by his personal doctor to get surgery immediately ... but Phillip wants to work through the pain and the risk so he can win next week.

Multiple "Idol" sources tell us ... when Phillip went back home to Georgia last Saturday ... his family doctor spent almost the entire stay by his side and was alarmed by what he saw -- Phillip wasn't eating and looked horrible. 

Phillip suffers from severe kidney problems and at the beginning of the competition it got so bad he had a stent put in as a temporary fix until he could have surgery. But the condition has worsened and Phillip's doc told him he needed surgery now. Phillip said he was not going to drop out of the show so the doctor told him he ABSOLUTELY had to go under the knife immediately after the finale.

We're told the recovery time for the surgery is at least 6 weeks.

Phillip's condition is taking its toll -- we're told the medication causes dry mouth, and it's had some impact on his singing.

Phillip has also missed some of the field productions that are shot for the show -- including the Ford commercials. Our "Idol" sources tell us they felt that making him go on location for these shoots were just too taxing.

Josh Hutcherson's nose was BROKEN IN A CRAZY BAR FIGHT ... would have been a much cooler explanation than the one he gave us yesterday.

The "Hunger Games" star was out in Beverly Hills ... sans nose bandages ... when we asked about the mystery surrounding his messed up honker.

In case you haven't been following ... earlier this month, Josh said he underwent surgery for a "broken nose" -- but he wouldn't explain how it happened.

His rep later insisted the nose wasn't broken ... and the surgery was merely to correct a deviated septum.

WHO TO BELIEVE???

Josh finally explained himself yesterday ... and his story could finally end the mystery forever!!!

With his face bruised and bandaged up, "Hunger Games" star Josh Hutcherson was spotted leaving a doctor's office in Beverly Hills on Monday ... after suffering a mysterious injury to his nose.

Hutcherson first tweeted about the injury on May 9th ... saying, "Just had surgery to fix my broken nose" ... and later his rep told us the actor had been diagnosed with a deviated septum.

But there's one big question -- how DID the 19-year-old movie star break his nose? 

Josh isn't saying ... and neither is his rep ... who told TMZ "no further details will be released."

Chicago Bulls star Derrick Rose underwent surgery on his left knee today to repair the torn ACL he suffered last month.

The Bulls leading scorer was injured in Game 1 of the playoffs against the Philadelphia 76ers with just a minute left. Rose played in barely half of the Bulls games this season after suffering a litany of injuries ... including turf toe, back spasms, a pulled groin and foot injuries.

No word on how long his recovery will take ... but there is a good chance he will miss a portion of next season as well.

Her name's Lydia Bright. She stars on a UK show called "The Only Way Is Essex" that's basically "The Hills" with English accents. And she DESPERATELY needs a bottle of sunblock.

Ass-PF 100, anyone?

There's a reason Rihanna's arm was hooked up to a bunch of needles and tubes yesterday -- sources close to Rihanna tell TMZ, the singer had been struck down with a bad case of the flu ... and required an IV drip.

Sources tell us, she started feeling really ill last week and saw a doctor on Thursday ... but by the time of her "Saturday Night Live" appearance, she still wasn't fully recovered.

As we first reported, Rihanna missed the SNL dress rehearsal because she was sick -- but show producers didn't buy her excuse ... insisting she didn't appear ill.

But looks might be deceiving -- because we're told Rihanna wasn't just ill during her SNL performance, she also continued to feel sick the next few days ... and her doc was forced to put her on Penicillin.

Soon after, Rihanna began to experience flu-like symptoms -- requiring IV treatment yesterday, which is when she posted the above picture on Twitter.

We're told she's feeling much better now.