Pope Francis said Wednesday he was "touched" by the many message of support received following his operation, as the Vatican announced that his condition continues to improve.

In his first tweet since surgery for an inflamed large colon on Sunday, the 84-year-old said: "I am touched by the many caring messages received in these days. I thank everyone for their closeness and prayer."

Vatican spokesman Matteo Bruni earlier said the pontiff is eating and is no longer receiving "infusion therapy", a phrase that typically refers to drugs administered intravenously.

Francis underwent a planned three-hour operation on Sunday for what the Vatican described as symptomatic diverticular stenosis of the colon.

"The post-operative progress of His Holiness Pope Francis continues to be regular and satisfactory," Bruni said in his daily media update.

The pope tweeted that he was "touched by the many caring messages received in these days"
The pope tweeted that he was "touched by the many caring messages received in these days" VATICAN MEDIA / Vatican Media

"The Holy Father has continued to eat regularly and infusion therapy has been suspended."

Tests confirmed "a severe diverticular stenosis with signs of sclerosing diverticulitis", he added.

Diverticula are small bulges or pockets that develop in the lining of the intestine. Diverticulitis occurs when they become inflamed or infected.

Sclerosis is normally defined as a hardening of tissue.

On Monday, Bruni said the pope would stay in Rome's Gemelli hospital for around seven days unless there were complications.