The round fragmented into hundreds of pieces and did "substantial damage" to bones, internal organs and blood vessels, Sava said.
Scalise was among four people shot by a lone gunman who opened fire on a group of Republican lawmakers practicing baseball at the Eugene Simpson Stadium Park. He has become more responsive and was able to speak with loved ones.
According to the spokesperson, Scalise underwent another surgery on Saturday.
A motive for the attack is still under investigation, the FBI and other law enforcement agencies said in a statement Friday. The shooter was an IL man, James Hodgkinson, who had lashed out against US President Donald Trump and Republicans over social media.
The person told The Associated Press on Saturday that investigators aren't sure of the significance of the names and don't know if it was a list of people he was targeting. Infection remains a considerable risk in the days and weeks during Scalise's extended hospital stay, Sava said.More news: Amazon purchase makes grocery wars hotter
The gunman, identified as 66-year-old James Hodgkinson of Belleville, Ill., died from injuries sustained during the shootout with police.
"Predicting the length of his hospital stay is hard today", said Dr. Jack Sava with MedStar Washington Hospital said.
Two sources close to the congressman's family said medical staff removed a tube that had been inserted into Scalise's abdomen to prevent fluid from going into his lungs while being sedated, The Baton Rouge Advocate reported. A spokesperson for MedStar Washington Hospital Center also could not be reached.
"On behalf of Steve and our children, I want to thank everyone from the bottom of our hearts for the incredible amount of prayers and warm wishes we have received since Wednesday's events", Scalise's wife, Jennifer, said in a statement Friday.