I myself had a Roux N Y Gastric Bypass back in 1998. Still to this day i occasionally will go very HYPO. Fortunately i have so far caught it before iI've passed out. It is a really uncomfortable/horrible feeling, gives me a better idea of how diabetics feel.
Doesn't happen to me very often and fortunately i've always been somewhere where i've been able to get something to eat/drink quickly. I've come close to passing out but touch wood.. not yet..
I'm in Scotland and my lowest blood sugar was 2.7mmol/l on our scale(48.6mg/dl US ).. was lucky in that my diabetic b/f was visiting and i tested myself using his meter..
Probably should get a meter myself for those times..