Largest I remember was a barium enema, about 2000 mL. The bag it was large, scary, and I was very uncomfortable with a balloon inflated in my behind that kept the barium solution from leaking. I was 24 at the time and enema newbe.I’m not into larger volume enemas like most of you. A nurse taught me in my 20s that I could get an effective cleanse with only about 1500 mL with a rectal tube and retaining it comfortably for a few minutes. It was better for me than punishing myself with higher volumes. Enemas should not be a risk to see how much solution we can hold. She recommended started out with just a half a bag and following with a full bag, which is easier to take in graduated amounts than trying to take a full bag at once.