Mike 'The Situation' -- In Rehab at Cirque Lodge for Prescription Pills

The Situation is undergoing rehab at the famous Cirque Lodge in Utah for prescription meds, TMZ has learned.

Several sources have told us The Situation is at Cirque for other substance abuse problems ... but as of now, we can only confirm prescription meds.

Our sources say The Situation is walking around Cirque, telling people he's gained weight -- and has made specific diet requests from the chef at the facility, hoping to get back into shape for the 6th Season of "Jersey Shore."

And just to make sure he gets his way -- one source tells us, Sitch is making damn sure everyone remembers how wealthy and famous he is.

We're told this is not the first time The Situation has undergone treatment for substance abuse.

1:50 PM PST -- Situation just released a statement ... claiming he has "voluntarily taken steps to get control of a prescription medication problem I had due to exhaustion."

He continues, "I have spent the past several weeks getting treatment for this problem and recuperating from my work and appearance schedule. I appreciate my fans support and love you guys."