TMZ has learned Real ... real name Ahmad Givens ... is getting treatment at Cedars-Sinai hospital in Beverly Hills.
A rep for Real -- who starred with his brother on the popular dating show 'Real Chance' -- tells TMZ he first got sick in January with what he thought was the flu.
We're told 33-year-old Real went back to the hospital at least 4 times and was initially told something was wrong with his liver -- but last week doctors informed him it was colon cancer.
Stage four generally means the cancer has spread to other parts of the body.
We're told the rapper-turned-reality-star will remain hospitalized at least until docs figure out what kind of treatment -- chemotherapy, radiation, or both -- he will require.
The rep says they expect a decision from doctors today.