Mr Rudd had a series of tests after suffering from severe abdominal pain and was admitted yesterday to Mater Private Hospital in Brisbane.

He had surgery to remove his gall bladder and was expected to spend a couple of days in hospital, according to his spokesman.

''Mr Rudd looks forward to resuming campaign activities next week both in his own electorate, elsewhere in Queensland and the rest of the country as appropriate in support of the re-election of the Government and Prime Minister Gillard,'' the spokesman said.

Julia Gillard wished the former leader a speedy recovery.

''I welcome his indication that when he's well enough again, he will be happy to campaign for the re-election of the Gillard Government my re-election as Prime Minister,'' she said. ''But ... that's for the future. For today, very, very much I would say to Kevin and his family we are all hoping, wishing, praying for a speedy recovery.''

The former prime minister's health scare triggered a short cessation of hostilities in the election campaign.

Opposition Leader Tony Abbott echoed the sentiments expressed by his opponent.

For more on this story, see the print edition of today's Canberra Times.