Researchers at the University of Maryland have developed a coin-sized device that clips onto underwear to measure flatulence accurately. The invention helps diagnose gut conditions like lactose intolerance by detecting hydrogen gas. Participants in a study often failed to notice their own increased gas production.
Brantley Hall and his team designed a small hydrogen-detecting sensor, comparable to a nickel in size, that attaches near the perineum on underwear. In a study with 37 participants, the device recorded flatulence after they consumed either 20 grams of lactose or sucrose on consecutive days, following a low-fibre diet baseline. Of the 24 people sensitive to lactose, the underwear detected over 1.5 times more farts than baseline on the lactose day for 22 of them, but self-reports matched only 50 percent of the time. “It’s literally like a coin flip,” Hall said. “People aren’t reliable narrators about their flatulence patterns.”The study highlights how one-third of lactose-intolerant individuals do not report symptoms, partly because they overlook their gas output. Hall noted that healthy adults fart between four and 59 times daily, averaging 32, though future research may adjust this figure lower. He plans to present the findings at the Digestive Disease Week 2026 conference in Chicago on 4 May.Tom van Gils at the University of Gothenburg praised the non-invasive approach. “Measuring flatulence right where the gas leaves the body by using non-invasive smart-underwear is interesting, especially given the good acceptability of the technique,” he said. The device could aid in diagnosing irritable bowel syndrome and evaluating gas-reducing treatments.
