What can be done for a belly button (navel) infection?
The nature of the anatomy is that the navel ("umbilicus") is a depression (an "innee") that can therefore collect lint and dirt. But the lint and dirt are usually not the cause of an infection of the navel. Because it can collect things, the biggest risk is a yeast infection from collecting moisture—either perspiration or not drying thoroughly after bathing. When it's dark and damp in there, a fungus can go crazy! Added to this is a bacterial infection from the irritation that scratching and picking can cause from the itching of the yeast.
Let's assume the worst: You got a yeast infection, then poked, scratched, and picked at it and now have a bacterial infection on top of it. First, you need to clean it. Peroxide is fine—but soap and water should do the trick. But you must dry it thoroughly to prevent the environment yeast likes. Put on it (in it) an antifungal cream—any diaper rash cream, like Desitin, will do nicely. Once the yeast clears up, the bacterial infection should resolve spontaneously. If not, then an antibiotic pill can be prescribed by your healthcare provider.
The take-home message here is that yeast loves moisture, be it in the vagina (with douching), under the breasts (with perspiration), or in the navel. So drying thoroughly is the answer to a yeast-free life for your navel. The same advice applies to between the toes, for drying these areas thoroughly will keep athlete's foot away as well.