Kevin Rudd in hospital

Kevin Rudd. Photo / Getty Images

Former prime minister Kevin Rudd has been admitted to a Brisbane hospital and will have an operation today.

A spokeswoman for Mr Rudd, who is running for the Brisbane seat of Griffith in the August 21 federal election, said the former Labor leader had experienced acute abdominal pain on Thursday.

He underwent a series of medical tests on Thursday night and Friday morning, she said.

"Based on specialist advice, he was admitted to the Mater Private Hospital around lunch time today," the spokeswoman said.

"Mr Rudd will have an operation to remove his gall bladder later today."

Mr Rudd's doctors had advised he was likely to be in hospital for a couple of days before being allowed home, she said.

"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 spokeswoman said.

Mr Rudd's wife Therese Rein also underwent surgery for a gall stone problem in January 2008 which she first experienced as a teenager.

And in August last year she was admitted to Cairns Base Hospital with stomach pains.

The Labor party has been criticised for not taking advantage of Mr Rudd in its election campaigning, particularly in his home state of Queensland.

Mr Rudd has to date confined his campaigning to his southeast Brisbane seat and ducked media questions.

The electoral commission on Friday formally declared Mr Rudd a candidate in Griffith.

He drew the last position on the ballot paper.

Prime Minister Julia Gillard speaking in Perth wished him well and a speedy recovery.

- AAP