Even though about two patients in five treated with antibiotics later required an operation, the advantages of a nonsurgical approach for those who were spared a recurrence of appendicitis include avoiding potential complications from anesthesia and surgery and a much longer recovery.

Still, you may want to know, why keep this organ, given that 7 percent of us will develop appendicitis during our lifetimes? The answer, my friends, is that the appendix is turning out to contain biologically useful tissue that may help prevent nasty gastrointestinal ills.

As long ago as 1913, a British surgeon pointed out that the appendix is a mass of lymphoid tissue that most likely protects against harmful infections. “The vermiform appendix of man is not solely a vestigial structure,” Dr. Edred M. Corner wrote in The British Medical Journal. “On the contrary, it is a specialized part of the alimentary canal, Nature having made use of a disappearing structure and endowed it with a secondary function by giving it lymphoid tissue to protect the body against the micro-organisms in the ileo-caecal region.”

Now, a century later, researchers have provided evidence in support of Dr. Corner, contradicting longstanding medical dogma to remove the appendix, not only when it’s infected, but whenever surgery for some other reason renders it accessible. Sixteen years ago, when I was about to be operated on for a strangulated intestine, I was asked if I wanted my appendix removed at the same time.

My response was “Hell no! It might be useful.” Though I could cite no biological evidence at the time, I suspected evolution didn’t produce and preserve the appendix for no reason. As it turns out, Heather F. Smith, an evolutionary biologist, and colleagues at Midwestern University in Glendale, Ariz., have found convincing evidence that “the appendix had apparently evolved independently more than 30 times in the course of mammalian evolution, suggesting that it provided some kind of adaptive advantage,” she told me.

“The appendix, with its high concentration of lymphoid tissue, stimulates and supports the immune system, especially when pathogens invade the gastrointestinal tract,” she explained. Furthermore, she suggested, we could do a lot better to preserve the health-promoting potential of this tissue.

Dr. Smith pointed out that, although great apes, several other primates and rodents have an appendix, only humans get appendicitis, a condition that predominantly afflicts people in industrialized nations who consume a Westernized high-carbohydrate, low-fiber diet that can result in calcified carbohydrate particles becoming trapped in the opening to the appendix.