A representative for singer says that he originally underwent tests for a suspected bladder infection but was ultimately diagnosed with a bleeding ulcer, according to Billboard.

He had originally canceled last Thursday's concert in Flint, Michigan, citing an unidentified illness within the band.

Due to his medical condition the singer has been forced to reschedule six upcoming dates on his North American tour.

The concerts in Asheville, N.C.; Nashville, Tenn.; Atlanta, Ga.; Lawrence, Kans.; Clear Lake, Iowa; and Lincoln, Neb have been postponed with new rescheduled dates to be announce soon.