It isn't that scary.

>Intra-rectal delivery of a liquid form of O2 known as conjugated perfluorocarbon, a compound historically used in clinics for liquid ventilation through airway administration, is highly tolerable and efficacious in ameliorating severe respiratory failure. Thus, by repurposing the distal gut as an accessary breathing organ, enteral ventilation therapy offers an alternative paradigm as an adjunctive means to patients who are in critical need of respiratory support.