First post here, and it’s a juicy one.
OK, so I have noticed a trend. When I eat at Chinese Buffet, I get bad diarrhea about 20 minutes after the meal is over. At Mongolian BBQ, I get bad diarrhea about 45 minutes after. Taco Bell is about 3 hours.
So, my questions are:
What is it about these foods that make me have diarrhea?
and
Physiologically, how are they able to effect my colon so abruptly after eating?
My mother has this same problem with garlic and bell peppers. I mean, if we’re out to dinner, she’s feeling the effects by the time we get home.
[sub]Hi mom! No, really, I’m not discussing your bowels with others![/sub]
What gives?
I hear you. Chinese Buffet will do it to me everytime. There’s no way that food could shoot down my alimentary canal that quickly.
I’ve always thought that when you eat a large meal your digestive tract notices this and kicks into overdrive. Some kind of Colon Red Alert to make room for what’s to come.
This may be a sign of a mild food allergy. This was how I found out I’m allergic to mushrooms - they always give me that reaction. As soon as I started paying attention, and correlating the reaction to what I’d eaten during that meal, it didn’t take too long to narrow it down to the mushrooms. (The difficult bit is that it would only happen eating out - even before I discovered my allergy, I didn’t add mushrooms to food at home.)
This is a common symptom in people with Irritable Bowel Syndrome, but it also occurs in people with lactose intolerance and other digestive ailments. It’s due to the gastrocolic reflex.
I have a related question: If something you eat gives you diarrhea almost immediately, does the food pass through your digestive system without all of its nutritional content being absorbed?
It’s not the new food being excreted, it’s the food that has already traveled through your intestines. It’s from meals eaten as long as 48 hours before.
Long-term diarrhea can certainly reduce overall absorption of nutrients, but doctors define that as longer than three weeks continuously.
I think, AudreyK, that the digestive system is reacting to what you just ate by causing problems with stuff you ate roughly 12 to 24 hours ago. In other words, you’re not pooping out something you ate 20 minutes ago.
I think it’s grease, myself. I’ve noticed that I often get diarrhea after greasy meals, especially those involving sauteed onions.
Hmmm…it could be that I’m allergic to onions, but raw onions don’t cause a problem. I still think it’s the grease.
TGIFridays is my bane. I’m always sick after eating there. In fact, I’ve wondered if there’s something not quite right with the food there, but no one else in the party ever gets sick, so it seems to be just me. I avoid the place anyway.
I’ve noticed the OP effect, and it’s real. I’ve seen bright green chopped spinach or parsley appears after 20 minutes of eating at a restaurant. And I hadn’t eaten these at any other time within at least a month so it’s not 24/48 hours old. I thought I was the only one who experienced this. The odd thing is that there was no other sign, no stomach rumbling, no pain. I even asked my doctor “how is that possible?” Naturally, he had no answer, probably not believing me.
Thanks, Exapno Mapcase and Sauron. (BTW, you wouldn’t believe how long I’ve wondered that.)
I suppose I could fast for a couple days and then consume large amounts of cheese and milk to see for myself. Yay, lactose intolerance. On the other hand, not eating for a couple days and then deliberately making myself sick would rank pretty high on my list of Stupid Self-Inflicted Tortures. So I think I’ll just take your word for it. 
IANAG, but I believe the major culprit here is the grease or fat. It may not be particularly apropos to the above discussion, but I am reminded of the story, perhaps apocryphal, of a modern-day comic (Robin Williams?) who had once, as a child, amused himself on a farm where geese (ducks?) were raised by tying a long string to a lump of fatty meat and feeding it to one of the fowl. Their “constitution” is such that the lump passes through in a manner of a few minutes. The lump was then passed along until in a half hour’s time there were 5 or 6 of them waddling around the barnyard in a rather odd convoy. Can anyone supply corroborative details?
I have the exact same thing!!. I did a test, For 1 whole month i didnt eat sweetcorn and then for lunch i had sweetcorn and vegetables and a pork chop. 20 minutes later i was running to the bathroom and i had bad diarrhoea and there was sweetcorn in it. No chance it was from 24/48 hours before that. I have had this for years. If im eating out, i have to either go directly home after the last mouthful has gone down, or stay at the place im eating at as i know that i will need the bathroom within 20 minutes. One day my ex hadnt finished his pint when i finished eating so i had to wait 10 minutes for him. Lets just say i didn’t make it home in time to use the bathroom, we had to wait for the babysitter to unlock the door and by the time she did, i had an accident 
I have had all the tests done and they say its ibs. Having a diagnosis doesnt help though, nothing they suggest helps. I just have to make sure im within reach of a bathroom and also to have some kind of air freshener with me
I thought “Irritable Bowel Syndrome” was a euphemism for being an asshole.
How about IZS? (Irritable Zombie Syndrome)
Not to dogpile but there’s just no way the “it’s not the food you just ate” thing is 100% true.
I think my record was like an hour… maybe 2? Spinach heavy first course at a restaurant… stopped at the bathroom on the way out of the restaurant… nothing but spinach.
When I was young, I’m told, I ate a whole unattended bowl of bright blue frosting which passed through me like lightning. What came out was bright blue. Not surprising, but still shocking.
It makes intuitive sense that fat goes ‘right through you’ because it’s all oily and stuff, but in reality, fat takes longer to digest than carbohydrate or protein because it is not water-soluable and requires the excretion of several different compounds along with thorough mixing to be processed. Also, foods that are majority fat and protein are digested almost completely by the human body. Most of the food waste in stool is from carbohydrate (plant-based) foods which tend to be fibrous.
In the OPs case, I agree with PPs that something he is eating is irritating his colon and causing it contract, expelling whatever is in there at the moment (before the water has been removed, hence diarrhea). It’s probably a specific food or additive causing this.
Anyway, I used to have quite a few digestive problems, but now that I have figured out what foods cause me troubles and stopped eating them I have none at all. I would suggest you avoid the restaurants that give you diarrhea if the only time you have this problem is when you eat there.
I’m going to crap out a zombie diarrhea in about 20 minutes!
Actually, what you do is follow an extremely bland diet for a week or so, and then gradually add in new foods that you suspect might be causing problems. I think that you start out on rice, applesauce, bananas, and lamb, no seasonings. I’ve only read about these diets, I’ve never had to follow one in order to pinpoint a food that causes problems, generally I know what I’ve just eaten that I don’t normally eat.
By the way, pepper (black, white, and red) is actually a fairly common trigger among the people I know with this problem. So you might have a problem with a restaurant seasoning everything with pepper.