Republican presidential candidate Rick Santorum will resume campaigning on Tuesday after his daughter was released from hospital and returned home, his campaign said.

"Rick and Karen are happy to announce that their daughter Bella has been discharged from the hospital and returned home earlier Monday evening," spokesman Hogan Gidley said in a statement.

Tuesday morning's campaign events remained canceled, he said, but Santorum added an extra stop in Gettysburg, Pennsylvania, for the afternoon.

His daughter, three-year-old Isabella, has Trisomy 18, a rare genetic disorder also known as Edwards syndrome that causes severe developmental disabilities. Most babies with the condition die before or during birth.

Santorum canceled a slew of campaign appearances in January when Isabella, or "Bella," was admitted to hospital with pneumonia just before Florida's key Republican primary.

She returned to the hospital on Friday, for undisclosed reasons.

Santorum -- a staunch opponent of abortion -- frequently mentions his daughter when meeting voters on the campaign trail. He has six other children with his wife Karen, a neo-natal nurse.

In 1996, their son Gabriel was born prematurely and died shortly after birth.

Santorum is running a distant second to former Massachusetts governor Mitt Romney in the race for the Republican nomination to take on US President Barack Obama in the November 2012 election.

Santorum, a former Pennsylvania senator, has nevertheless vowed to stay in the race, and is hoping for a big win in his home state later this month to reignite his candidacy.