Colloidal Silver possesses antiseptic and antimicrobial properties and readily kills bacteria through indirect means in vitro, meaning when exposed to biological systems outside of their native environment, say in a petri dish. However, it's application for treatment of most conditions, including hemorrhoids, although claimed, has never been scientifically proven.
It's possible that with topical application, a bacterial infection might be arrested, leading to a decrease in inflammation. However, this would not remove the underlying condition, nor cure it.
For detailed information on hemorrhoids and available treatment options visit Hemorrhoid Treatment for more information.