Nystatin is an antifungal agent used to treat a variety of fungus infections, but it is exceptionally popular to treat skin and mucosal membrane infections caused by varieties of Candida albicans, a yeast-like fungus that is commonly found in the gastrointestinal tract. The drug works by binding to sterols in the fungal cellular membrane altering the permeability to allow leakage of the cellular contents and destroying the fungus. Side effects are diarrhea, nausea, and stomach pain.