Yup, I was almost exactly the same. I did feel better after a few days, but was always dizzy, and NEVER had a bowel movement.
I honestly don’t know the answer. When I was dealing with an eating disorder I would regularly go 2-3 days without food of any kind and then a day or so of eating almost nothing, so I’m going to guess at least 4 days although it’s probably more.
I did the same thing in high school, though I always drank diet coke for the caffeine. Since I had little else in my system, I’d shake or feel buzzy almost constantly.
I went through a period of about 4 weeks where I ate only on Sunday. The rest of the week was water only. Monday there would be mild hunger, Tuesday not so bad, Wednesday excruciating, and Thursday through Saturday were no problem at all. I know it was at least 4 weeks but it was a long time ago and could have been 5 or 6.
It was more of an experiment than anything else.
I know even within the RNY community cutting the vagal nerve is not universal. I really wanted the DS, since I had 200+lbs to lose but insurance said no. I think I did ok with RNY, though, so no complaints. As for the full thing? I hear ya – my body has actually done this thing where the last bite before “oh shit, I’m going to puke now” I get one massively loud hiccup. It is my “soft warning” sign to stop eating. If I ingore it, I will be in pain in the bathroom. I have become an expert at dealing with the low sugar, though – it happens only when I have gone several (like 9 or more) hours without eating, as soon as I get the first symptom (which for me is a little lightheadedness) I eat a slice of cheese and things level off pretty quickly. Ok, done with the hijack. Continue on 
Not too long, I’d say 24 hours when I had influenza or something.
Which sort of worries me, if I skip breakfast (which I usually do) and lunch, I start feeling crappy in the afternoon. I get headaches and just generally feel bad.
I’m a thin guy of medium height, maybe I just don’t have enough reserves not to be regularly eating.
I’ve never intentionally fasted; I get all weak and irritable if I go without food for more than a few hours (I’m eating a snack now so that I’ll be able to make it through my 4:00-6:00 rehearsal without doing any murdering). I can’t remember ever going without food for 24 hours; usually when I’m sick I at least have some toast or something.
Six days due to illness. I thought I was a cute female Japanese secret agent (I’m a 6’5" blue eyed male) and a small black paper envelope before I was finally hospitalized. Not much fun, but the envelope thing still puzzles me.
I grew up Jewish but became really interested in the Baha’i faith for a few years and almost declared. After a while I realized that while I think it’s really beautiful and interesting it’s not quite for me. I do kind of miss fasting though.
I’ve gone maybe a couple days while sick, I might have had a few crackers or maybe some Jell-O.
In my drinking days I’d regularly go all weekend without solid food, but I suppose the massive quantities of beer disqualifies that.
Due to absentmindedness, maybe 36 hours with nothing but Diet Pepsi.
I’ve done a couple of days on water and broth because of sickness, and the 30-Hour Famine once. The famine actually wasn’t terrible, if you kept yourself occupied and not thinking about food.
Cool. Thanks for the clarification.
I tried 24 hours once for religion, but 16 hours in I passed out from low blood sugar.
When sick I easily go 3-4 days on minimal soup and crackers. I just need something to run on. Unfortunately I go straight past lightheaded to nausea, shaking and blacking out.
One time in college, long story short, I was too depressed to eat. It went on for at least 4 days only drinking water and stuff, and a week total hardly eating anything until I got some news that brought me out of it.
I got a really bad case of the flu freshman year of college during finals. No roommate, friends AWOL studying. I didn’t eat for about four days; barely had the energy to walk 20 steps down the hall for water fountain and bathroom, much less outside the dorm for any sort of food. After 4 days I made it to the health center, got some pills that added vomiting to my symptoms. In short, all I ate in a 7 day period was about 35 saltine crackers. My parents had to come pick me up and drive my car home because after that week, I was still kind of sick and weak and the dorms were closing for the holiday. I didn’t eat normally again for probably 2 weeks after that.
I’ve never intentionally gone any length of time without food. I’ve had 2 horrible hangovers that ended up making me not eat for a bit, but no more than 30 hours or so. Nowadays I eat every couple hours during the day.
I’ve gone over thirty at least a half dozen times in the past couple years and broke a 44 hour fast about two hours ago. Didn’t eat anything from 9:00 PM Monday until sometime after 5:00 PM today, though I did have some diet soda and chewed some gum last night.
I’ve often forgotten to eat on the weekends. And sometimes on the days I’m too busy running around at work. And then I’m too tired to contemplate cooking. Lots of coffee.
The sad thing? When I eat, I like eating the good food. Food that will make the gods weep and which induces gustatory orgasms. Yeah, I have a weird relationship with my stomach.
I don’t suffer any side effects that I’ve noticed, either.