Laboratory studies on three "very small" growths removed Friday from President Reagan's large intestine, and a tiny patch of tissue shaved from the right side of his face, all showed no signs of cancer, the White House announced yesterday.

A terse, two-line statement released by White House spokesman Albert R. Brashear said only that "final laboratory evaluation on the three intestinal polyps and facial tissue removed from the president yesterday has been completed and all are benign. The president was informed of the results by his physician at Camp David this morning."

The President and Mrs. Reagan flew to the Maryland mountain retreat Friday evening for the holiday weekend after he underwent nearly six hours of tests at Bethesda Naval Medical Center to monitor his health after surgery for colon cancer last July.

All tests were normal, with no sign of recurrence of cancer in the colon or elsewhere in the body, according to the brief statements issued yesterday and Friday night.

Brashear said yesterday morning that he would have no further comment.

Under orders from First Lady Nancy Reagan, who was reportedly disturbed about the extensive medical information released at the time of last summer's surgery, White House officials have refused to answer questions about the president's health or provide further details on results of Friday's tests.

Based on available public information, medical specialists not associated with Reagan's care said yesterday that the findings were encouraging and that the new discovery of tiny intestinal growths, or polyps, is not unusual in a patient with the president's history.

Like some older Americans, the 74-year-old Reagan may simply be "polyp prone" and in need of careful longterm follow-up, said Dr. Nelson P. Trujillo, a Washington gastroenterologist and clinical professor at George Washington University School of Medicine. "From a med-ical point of view, everything is okay," Trujillo said.

"It is not unusual, in a patient who has had prior polyps or prior cancer, to have small polyps seen afterward," said Dr. John L. Cameron, chief of surgery at Johns Hopkins Hospital. He said this occurs in more than 25 percent of cases. Detected early, "they are almost invariably benign. There isn't anything to be concerned about," Cameron said.

"Nothing is a surprise as far as I can tell," said Dr. Stanley B. Benjamin, now chief of gastroenterology at Georgetown University Hospital and formerly on the Bethesda Naval Hospital team that examined Reagan early in his first term. "I am extremely optimistic."

Doctors first discovered a polyp in Reagan's lower intestine in a routine examination in May 1984. It was benign. In March 1985, another polyp was found, as well as evidence of blood in his stool. He did not have a complete examination of his large intestine until last July 13, when a colonoscopy revealed a large malignant growth 2 to 3 inches long. The growth and about one-third of his colon was removed.

Specialists suggested then that there was a better than 50-50 chance that his disease was permanently cured. But like all cancer patients, Reagan must undergo regular exams in case seeds of the original cancer have spread to other parts of his body or that a second cancer might be growing within his intestine.

The extensive 6-month follow-up Friday afternoon included blood tests, X-rays, a CAT scan to visualize organs, such as the liver, to which cancer can sometimes spread, and a colonoscopy. The colonoscopy involves moving a flexible, lighted tube through the colon to search for polyps.

A White House statement said that the three polyps found Friday were "very small" -- smaller than 2 millimeters or about one-twelfth of an inch each. They were removed at the time of the colonoscopy to check for cancerous cells.

The laboratory procedure usually takes 24 to 48 hours, but was completed more quickly in the president's case.

In addition to a propensity for colon polyps, Reagan is also prone to skin growths, perhaps because of lifelong exposure to the sun. In addition to the small growth removed Friday, he had two malignant growths removed from his nose last year. Such skin cancers are also more common with advancing age and are usually not serious.