Solving the Mystery of I.B.S.

Experts are starting to untangle the biological underpinnings of this common yet perplexing disorder. What they’re finding could offer clues on how to treat it.

The Unknowability of Other People’s Pain

While my father was alive, it was impossible for me to imagine his agony.

You’re Missing Microbes. But Is ‘Rewilding’ the Way to Get Them Back?

The science behind the idea of restoring the intestinal microbiome to an ancestral state is shaky, skeptics say, and in some cases unethical.