The former The Smiths frontman axed several gigs on his North American tour last month after being admitted to a hospital in the US for treatment, with a spokesman blaming a bleeding ulcer.
Now it has emerged the veteran rocker has been diagnosed with Barrett's oesophagus, an abnormal change in cells in the throat.
Symptoms can include chronic heartburn, difficulty swallowing, chest pain and vomiting blood, and the condition is associated with an increased risk of oesophageal cancer.
Morrissey was also treated for concussion but remains upbeat about his health, joking with fans that he has now suffered every illness known to man, and he has vowed to return to the stage in time for his gig in Las Vegas later this month.
In a statement, the star writes: "The reports of my death have been greatly understated. Once admitted to the William Beaumont Hospital at Royal Oak in Michigan, I received treatment for concussion, a bleeding ulcer, and Barrett's esophagus (sic).
"The positive from all of this is that there are now no known ailments left for me to try. I am fully determined to resume the tour on February 9 at the Chelsea Ballroom in Las Vegas."