Well, my experience was pretty similar but my second treatment was in the next morning, a few hours before tunneling.
And instead of sleeping it off I watched the whole thing on a monitor there, just for me. As the physician described what I saw to me, I kind of went in a haze until I realized someone was calling my name. "Mr. leterrible, are you okay!? Mr. leterrible, are you okay!?"
Recognizing him I said:"Woooooww! That's the best shit I've ever had!" The nurses started to laugh.
"Errm...I mean the morphine!"
And I got bowel pictures to remember the ordeal...
