The present invention provides an adaptor that is suitable for attachment to an endoscopic device for delivery of a secondary gas. The adaptor can comprise a substantially cylindrical body with a two, opposing closed ends, two fluid transport channels extending through the cylindrical body and opening at the closed ends, and an inlet port extending outward from the cylindrical body and being in fluid connection with one of the fluid transport channels. The adaptor may be used in endoscopy methods and is particularly useful for adding a secondary gas source in an endoscopy procedure.