In a small randomized controlled trial, patients who underwent endoscopic sinus surgery had no differences in outcomes, including symptoms and infections, whether they took an antibiotic or placebo after surgery. The only reported difference in outcomes was in side effects, with patients in the antibiotic group 10 times more likely to report symptoms like diarrhea. The authors note that their study looked at only routine endoscopic sinus surgery and not surgeries that use dissolvable nasal packing, which may be a future area of study. “For routine sinus surgery, antibiotics are unnecessary and may cause more complications like gastrointestinal side effects,” said study co-senior author Eric Holbrook, HMS associate professor of otolaryngology head and neck surgery and director of the Division of Rhinology at Mass Eye and Ear. “There have been studies that have suggested antibiotics might help or maybe they don’t, and we sought to clear that up through a rigorous randomized trial.”