Senator Patrick Brazeau is in critical but stable condition in hospital after he was found seriously injured in his home Monday night.
Mr. Brazeau was admitted to the Hull Hospital around 1 a.m. Tuesday and underwent surgery. His life is not in danger and his condition is improving, said hospital spokesman Benoît Gauthier.
The circumstances of the senator's medical emergency remained murky.
Shortly after 10 p.m. on Monday night, provincial police officers were called to a residence in Mayo, Que., to assist ambulance paramedics, said Sergent Marc Tessier, a Sûreté du Québec spokesman.
He said he could not provide more details because the incident didn't involve criminal activity.
According to court records, Mr. Brazeau's current address is at a cottage owned by his girlfriend, in Mayo, a small Outaouais town 45 kilometres east of Ottawa.
One of Mr. Brazeau's lawyers said the senator's upcoming trial in Ottawa for fraud and breach of trust may have to be postponed.
Defence lawyer Christian Deslauriers said he was supposed to meet Mr. Brazeau on Tuesday to prepare for the trial.
Instead, he had to go to the Hull Hospital in the morning to look for his client.
"After I showed that I was his lawyer, they confirmed to me that he had indeed been admitted to the hospital but I couldn't talk to him."
The 41-year-old Mr. Brazeau was appointed to the upper house by Stephen Harper's government but had been kicked out of the Conservative caucus because of his legal problems.
His suspension from the Senate was lifted this summer when Parliament was dissolved because of the federal election.
Last October at the Hull courthouse, Quebec Court Judge Valmont Beaulieu granted Mr. Brazeau an unconditional discharge after he pleaded guilty to assault and possession of cocaine.
The assault charge stemmed from a 2013 incident with a female acquaintance. The following year, police arrested him and found 0.6 grams of cocaine in a pouch in his pockets. He said he had seized the drug while working as a bar manager.
Mr. Brazeau's Ottawa trial, scheduled to begin March 29, stems from an RCMP investigation into senate housing and living expenses.