President Reagan is making a "virtually trouble-free" recovery from surgery to remove a cancerous tumor in his colon and "is beginning to question some of the restrictions that are on him at the moment" at Bethesda Naval Hospital, presidential spokesman Larry Speakes said yesterday.

"I think the president is, in his own mind, ready to be 'up and at 'em,' " Speakes said. "He's already talking about his schedule and returning to work."

The day after he was told that the tumor in his large intestine was malignant, Reagan was described by Speakes as "not one to dwell on anything of that type" and holding "a very optimistic and enthusiastic outlook."

At the White House, chief of staff Donald T. Regan was described by Vice President Bush as "doing a darn good job of running the White House" in the president's absence.

Regan took a telephone call from British Prime Minister Margaret Thatcher expressing sympathy for the president, and later relayed her hopes for a speedy recovery to Reagan in a 25-minute meeting at the hospital.

Regan also reported to the president on a regularly scheduled Cabinet breakfast at the White House and a meeting with House and Senate Republican leaders. The president later issued a statement declaring that "we are willing to meet the deficit head-on" and urging congressional negotiators to reach a compromise.

Regan appeared to be serving as the single assistant carrying information to the president. Bush and national security affairs adviser Robert C. McFarlane have not met with the president since his surgery, but are expected to see him in the next day or so, Speakes said.

"I think Don [Regan] would be the first one to tell you he's not running the country, that the president is, and they're keeping in close touch . . . and the chief of staff is not making any decisions that the president does not wish him to make," Speakes added.

At a photo session, Bush told reporters, "Life goes on and the news is so encouraging" that it is "just as if the president were on vacation." Bush repeatedly used the phrase "life goes on."

At the hospital, Reagan walked around his suite, viewed flowers and plants sent to him, read a national security briefing paper, talked congressional politics, approved a statement on arms-control negotiations, napped and read a "A Treasury of Will Rogers."

The White House said his vital signs are "stable" and the president is in "excellent spirits." His temperature, which had been slightly elevated, was said to have returned to normal.

Reagan will remain hospitalized for the seven- to 10-day period his physicians had estimated, Speakes said.

The president remained connected to an intravenous unit, receiving antibiotics, and had a tube through his nose to remove gas and liquid from his stomach.

Speakes said there had been signs of "resumption of normal digestive activity" in the area where surgeons removed a two-foot-long section of Reagan's lower intestine, but no "conclusive" evidence yet of bowel activity, a key indicator of progress toward recovery.

Speakes said Reagan had not dwelled on or asked others about the news that his tumor was malignant. Earlier, officials said he received word in a five-minute talk with his doctors.

"The president received a very adequate explanation for the findings," Speakes said. "The president is basically a very solid, a very courageous, very optimistic individual, and this is perfectly within his nature to address problems like this . . . . It's a solid, straightforward, you know, 'Let's get about the business at hand' type approach, and that's exactly the way he approached this."

With his wife, Nancy, the president viewed flowers and plants sent to him. "This is the best medicine I could have," Reagan said, according to a White House statement. He asked that some of the flowers and plants be shared with children in the pediatrics ward, who had sent him cards, the White House said.

Speakes said Reagan was eager to leave the hospital. "I just think he'd like to jump out of bed and run down the hallway and jump in the car," he said.

Asked whether Reagan was feeling any discomfort, Speakes quipped, "A little discomfort when he does his sit-ups."

He added, seriously, that Reagan feels "a little discomfort" when he rises or sits in a chair and that the president is being steadied at the elbow when he walks.