Max Key has been hospitalised while on holiday in Croatia.
The son of former Prime Minister John Key revealed the incident on Facebook, saying he had been admitted due to a "gnarly stomach bug".
- Max Key quits job, leaves for OE
- Max Key launches Instagram account documenting John Key's personal life
- 'Hashtag vote for Key' - Max Key re-ups bid for PM
"Had to get a gastroscope which was the worst thing I've ever had hahah, but still smiling and happy to be alive," he wrote.
Pictures of Key smiling in a hospital bed and wheelchair accompanied the post.
A gastroscopy is when a camera is used to view the stomach, inserted through the mouth and down the oesophagus.
Key left New Zealand to travel earlier in the year, visiting Europe, the United States and Canada.
"I'm looking forward to getting away from the pressure I feel myself under here in NZ, as well as challenging and teaching myself how to be happy and satisfied with my own company," he wrote in the post announcing he was leaving NZ.