Keith Duffy is out of hospital after 72 hours of illness which left his Boyzone bandmates to continue on without him in Thailand.
The 44-year-old was hospitalised before the weekend as the band were due to perform in Bangkok.
The Dubliner said on Instagram that he had suffered a bowel infection and a viral infection, and thanked hospital staff at the World Medical Centre hospital in Thailand for their help.
"Seventy-two hours of a fever of 38/40 degrees with diarrhoea and vomiting caused by contaminated food from bad hygiene in preparation.
"The worst bad health experience of my life," Duffy said.
"A secondary bowel infection and viral infection.
"These ladies are my saviour, they are saints - thank you, ladies, I love you.
"You've given me a whole new perspective of selflessness I will never forget. God bless you all and thank you again."
Boyzone took to the stage as a trio at the Thunder Dome, Pak Kret on Friday as part of their 25th anniversary tour in south-east Asia, Australia and New Zealand.
His bandmates thanked fans for their support and confirmed Keith would be flying to Adelaide for their next show tonight.
"After three long days in hospital in Bangkok, Keith is back on his feet and will be flying to Adelaide to join the Boyz for their show there.
"Big love and thanks to all the wonderful staff that have looked after him and for all the messages of support that you guys have sent out to him."
Ronan Keating (42) had said Duffy went on a "downward spiral" before being taken to hospital.
"He took ill before the show, he just went on a downward spiral," he said.
"He came to the gig, he had a massive, really high temperature, the doctors arrived at the gig and they said it wasn't possible for him to go on in the state he was in," he said.
A statement from the band on Thursday said Duffy had been taken to hospital "on the advice of the local medical team".
Asked about the Bangkok gig without Duffy, Keating said it was "hilarious".
"We had considered certain things, but not others.
"I had to take some of Keith's vocals and I didn't know the words," he said.
In January, the band said farewell to Irish fans as they played their last-ever gig in the 3Arena, having announced they would split for good after this tour.
Keating thanked fans for their support over the years and paid tribute to former band member Stephen Gately, who passed away in 2009.
"The four of us, the five of us, want to thank you," he said.