Belly button water odor usually can be caused by two reasons. 1, it may be the soft tissue inside the stomach infection caused by the stomach because the stomach because of the deeper so it is easy to hide bacteria, if you are not careful inside the stomach has a small lesion, the bacteria can easily invade the wound and thus appear to have a bacterial infection. 2, it may be the belly button eczema and caused, this condition is usually the surrounding red, swollen, hot, pain, some inflammation secretion, which is the reason why there will be a water odor. Serious will appear around the red, swelling, heat, pain, some inflammatory secretions, that is, there will be the cause of the odor of the water. 2, may be caused by the belly button eczema, this is usually inside the stomach or around the small herpes, these herpes usually penetrate after the white transparent or yellowish liquid, usually accompanied by itching.