Rick Santorum has canceled today's planned appearances in Florida and on NBC's Meet the Press after his three-year-old daughter Bella was admitted to Children's Hospital of Philadelphia. Bella is experiencing complications relating to Trisomy 18, a life-threatening genetic condition that causes a wide array of physical and mental problems, The Philadelphia Inquirer reports. Bella, one of six children in the Santorum family, has been mentioned publicly by her father on multiple occasions, often in defending his pro-life stance. 

Speaking to a group of Christian conservatives in Iowa shortly before he won that state's caucus, Santorum said:

"I have a little girl who's 3 1/2 years old. I don't know whether her life is going to be measured - it's always been measured - in days and weeks. Yet here I am . . . because I feel like I wouldn't be a good dad if I wasn't out here fighting for a country that would see the dignity in her and every other child."

Appearing on behalf of her father in Sarasota today was Santorum's 20-year-old daughter, Liz, The Palm Beach Post reports. She told the crowd of about 250 gathered in an airplane hanger, "My dad wishes he could be here with all of you today. My dad today is exercising his most important role; being a dad." A campaign spokesman told People magazine that reality stars Jim Bob and Michelle Duggar of TLC's 19 Kids and Counting will also be filling in for Santorum on certain campaign stops until he's able to resume his schedule. "Rick himself intends to return to Florida," the spokesman said.