When the United States started requiring background checks in 1994 for people buying handguns from dealers, it was a rare chance to see whether a gun-control measure really worked. Are you an editor or a writer? Writers and editors work together all the time, but the two clans are somewhat mysterious to one another. The treatment may sound appalling, but it works. A new study has found that an infusion of feces from a healthy person into an ailing patient’s gut was significantly more effective than a traditional antibiotic treatment — raising hopes that the unconventional approach could one day help combat obesity, food allergies and a host of other maladies. A little more than a year ago, I wrote a piece in Scientific American about fecal transplants — replacing the stool in someone’s colon with stool donated by someone else — as a treatment for the pernicious, recurrent diarrhea caused by Clostridium difficile infection. So it’s 2013 everybody.