How can I repair water damage under my linoleum bathroom floor?

My kitchen floor got water damage in the sub flooring, we had to have it replaced, as a matter of fact when my son and his friend pulled up the floor they found mold and had to even remove the floor beams (large boards holding the floor up) to get all of the mold.

You will have to remove the linoleum floor to examine the damage to the sub floor. If the sub floor is wet or has been wet you may have to replace it. The linoleum floor will hold the moisture in the wood and won't allow the floor to dry out.

Is your floor on a crawl space or on a basement that is finished or on a slab of concrete? If on concrete yes you will pull up but if you can see underneath it by going into crawl space or removing tiles from basement ceiling do so and see extent of damage. If not bad and no mold yet,then see if you can dry it out with fans pointed up to that area. Also add some dehumidifiers to dry out area at the same time if crawl space has a concrete floor. That's what I would try first if that doesn't work then removal is your only option and you must keep an eye on it to avoid mold on beams so that you don't lose them as well. Remember that if in kitchen cabinets and appliances are heavy as well as if in bathroom. So you really need to tackle this right away.