A water bottle assembly for use with an endoscope, the water bottle assembly comprising: a water bottle having a neck portion with threads on the exterior surface thereof; and a water bottle cap having walls and threads formed on the interior surface thereof; wherein the water bottle assembly further comprises: an adapter comprising: a substantially tubular body having an interior surface and an exterior surface and having an upper body portion and a flared lower body portion; the upper body portion having threads on the exterior surface thereof and being removably affixable via the threads to the water bottle cap; the flared lower body portion having threads on the interior surface thereof and being removably affixable via the threads to the neck portion of the water bottle; the adaptor further comprising a gas inlet port extending outward from the exterior surface of the tubular body and having a central passage extending through the tubular body and opening on the interior surface of the tubular body; and one or more tubes affixed to one or more openings formed in the water bottle cap, at least one tube extending through the water bottle cap, through an interior passage in the adaptor, and into the water bottle. a water bottle having a neck portion with threads on the exterior surface thereof; and a water bottle cap having walls and threads formed on the interior surface thereof; wherein the water bottle assembly further comprises: an adapter comprising: a substantially tubular body having an interior surface and an exterior surface and having an upper body portion and a flared lower body portion; the upper body portion having threads on the exterior surface thereof and being removably affixable via the threads to the water bottle cap; the flared lower body portion having threads on the interior surface thereof and being removably affixable via the threads to the neck portion of the water bottle; the adaptor further comprising a gas inlet port extending outward from the exterior surface of the tubular body and having a central passage extending through the tubular body and opening on the interior surface of the tubular body; and one or more tubes affixed to one or more openings formed in the water bottle cap, at least one tube extending through the water bottle cap, through an interior passage in the adaptor, and into the water bottle. an adapter comprising: a substantially tubular body having an interior surface and an exterior surface and having an upper body portion and a flared lower body portion; the upper body portion having threads on the exterior surface thereof and being removably affixable via the threads to the water bottle cap; the flared lower body portion having threads on the interior surface thereof and being removably affixable via the threads to the neck portion of the water bottle; the adaptor further comprising a gas inlet port extending outward from the exterior surface of the tubular body and having a central passage extending through the tubular body and opening on the interior surface of the tubular body; and one or more tubes affixed to one or more openings formed in the water bottle cap, at least one tube extending through the water bottle cap, through an interior passage in the adaptor, and into the water bottle.