Topical Probiotic Sinus Irrigations for Treating Chronic Sinusitis

This study is testing whether rinsing the sinuses with a probiotic solution (good bacteria) can help people who have ongoing sinus problems — a condition called chronic rhinosinusitis (CRS). Participants have already had sinus surgery and are currently experiencing a flare-up. Researchers want to see if probiotics can reduce inflammation and infection compared to a regular rinse. You may be eligible if... - You are 18 years of age or older - You have been diagnosed with chronic rhinosinusitis with a current flare-up - You had functional endoscopic sinus surgery more than 12 months ago and your sinuses are open - You are willing and able to follow study procedures and complete questionnaires You may NOT be eligible if... - You are currently using topical antibiotic rinses and are unwilling to stop - You have a terminal illness, are immunocompromised, or have cystic fibrosis or certain autoimmune diseases - You are pregnant or breastfeeding - You have taken oral antibiotics or corticosteroids in the past 2 weeks - You currently have symptoms of an upper respiratory infection (fever, runny nose, sore throat) Talk to your doctor to see if this trial is right for you.