I recently had minor surgery on a part of my body I’d rather not specify–and part of the preparation was fasting for a day before. I heard that doctors could ask you you fast, not even drink, for even longer–4 days or more. Asked my dad about this and he thought it was because putting me under would make me bring up/push out/let loose everything in my stomach/rectum/bladder…somehow. This sounds plausible, but is it right? And by what mechanism does that work? Thanks.
I believe the main concern is vomiting while under general anesthesia, which could cause you to choke on your own hurl and die. Having an empty stomach reduces the chances of that catastrophe.
I understand it has to do with the possibility of vomiting while under anesthetic. That could be very dangerous if it got into your lungs.
You fast before general anaesthesia because of the risk of vomiting and then inhaling the vomit. In my experience (25+ general anaesthetics) the fast is usually 8-12 hours with no food and 4-6 hours with no water. You vomit because they use drugs that paralyse you, so all your muscles relax.
If you’re having surgery on the GI tract they can ask you to do bowel prep which basically cleans out the bowels (you drink a powerful laxative, such as picolax) so that it’s easier for them to operate, and reduces the chances that you’ll get faeces where they shouldn’t be.
It’s very doubtful that they’ll make you refrain from drinking for 4 days.
I had major surgery in 2006 that required bowel prep, I had to fast (no food, clear liquids onl) for two days and do bowel prep the day before.
Yeah, wouldn’t that likely kill you? I’m thinking of the 3-3-3 rule: 3 minutes w/o oxygen, 3 days w/o water, 3 weeks w/o food.
If they admit you they could give you IV fluids. But at my hospital a bed costs £500+ a night (even though it’s NHS), so that would incur over £2000 of charges, for no benefit. The charges being paid are things like staff costs, and I only know it because we have to cost for stuff like that for clinical trials.
I can’t imagine a doctor asking you to go 4 days without water - depending on the temperature and humidity, the average person can last 2- 10 days without it, but that’s bringing you to the point of death.
http://www.survivaltopics.com/survival/how-long-can-you-survive-without-water/
Ah, yes, I hadn’t thought of that. Wouldn’t the be some extraordinary circumstance, though? I’ve known a lot of people going in for all kinds of surgeries and I’ve never heard of anyone having to forgo water for 4 days.
Sort of related.
When I was about 6 or 7 I went into hospital for a surgery, but due to a shortage of donor blood the surgery was postponed at the last minute (I’d actually been given a pre-med). They decided that the best course of action was to reschedule the surgery for the following friday evening, which was 2 days away. They also decided that I would remain admitted and continue to fast for those 2 days. But, they allowed me to drink clear fluids up until midnight the night before the operation. It wasn’t easy on me being in a ward with 5 other kids who were eating for those 2 days. 
After the surgery I remained nil by mouth (nothing, not even water) for 7 days. That was absolutely horrible as my mouth had completely furred up, and my lips had split despite the nurses doing their best to prevent that.
In the book “Intern”, by “Dr. X”, the author quotes a senior surgeon who found some stray food in a patient’s stomach and called it “last summer’s corn”.
Pigs are more closely related to humans than most other domestic animals, and it’s easy to imagine the insides of a human while looking at those of a pig. In a slaughterhouse I worked in, one fellow’s job was to pull intestines out of the body, which was split from neck to pubis, as it hung from an overhead conveyor chain by one foot, and clear their contents out of what would become casing into one chute before throwing the casing into another. There was quite a lot of stuff in there (OK, I don’t know if that is strictly comparable to humans). The body with its intestines intact was very nice and clean inside, but with the intestines cut things could get messy fast. At which point, a human patient in the same predicament might only have a little more life left in him than the hanging pig.
Yea I’m not sure why I had the four days in my head–thanks the the input anyway.
Like friedo and RealityChuck mentioned, vomiting while under general anesthesia could lead to aspiration pneumonia