Published Sunday, 23 September 2012
The gig at the Odyssey has been rescheduled for November. (© Getty)
A statement confirmed the 'All Night Long' singer was forced to make the decision after visiting the doctors.
"They confirmed that he needs to respond to treatment and should make an excellent recovery," it read.
Lionel is said to be extremely disappointed that he has had to reschedule his appearances at both the Belfast Odyssey and the O2 in Dublin.
He said he "always receives the warmest of welcomes" in Ireland and that was why he had chosen to start his tour here.
The music star is looking forward to getting back later in the year to perform in Dublin and Belfast for the gigs which are now rescheduled for November.
Wednesday's gig at the Odyssey will now take place on 11 December 2012.
Tickets holders are asked to retain their tickets for the new dates to gain entry.