It is unlikely that Columnaris will go away on its own. Once the bacteria infects a fish, it will continue to cause damage to the fish's skin, fins, and gills. If left untreated, the infection can quickly spread and lead to death of the fish. Even though the fish's immune system can help to combat the infection, it is often not enough to completely eliminate the bacteria. It is important to address the issue with proper treatments as soon as possible, to prevent the spread of the disease to other fish and to minimize the damage to the infected fish.