Thatcher, 87, was admitted to the hospital last week and released Friday, the BBC said.
After she was admitted, friend and former adviser Lord Bell said she was having a "minimally invasive" surgery.
"She's very tough. The doctors are perfectly happy. They say the operation has been completely satisfactory," he said.
Now, Thatcher is said to be "doing well" after the surgery.
Thatcher has suffered from ill health in recent years; she had a series of minor strokes in 2002, and her daughter, Carol Thatcher, has previously said that her mother struggles with dementia.