Anyone who dines out with any regularity has likely experienced a restaurant meal gone bad. Most people assume that when a meal out ends in serious digestive upset, they must have gotten food poisoning. But while food poisoning is common enough – the Centers for Disease Control and Prevention estimates that 48 million Americans experience foodborne illness annually – there are other reasons that a nice evening out can end in the bathroom.
• "White Tuna" – the fishiest sushi of them all: Those of us who never studied marine biology must be forgiven for not knowing the best-kept secret of Japanese restaurateurs: There is no such fish as "white tuna." And yet, white tuna has shown up on virtually every sushi menu I've ever seen. So which fish, you may ask, are you actually getting when you order white tuna? Well, that depends.
If you're lucky, you're getting albacore tuna. If you're not, you're getting a fish called escolar – aka "snake mackerel." Escolar contains an indigestible waxy ester called gempylotoxin that has a strong laxative effect in people. According to the U.S. Food and Drug Administration's "Bad Bug Book," when escolar is eaten in a large enough portion, it will result in cramping, diarrhea or anal leakage an average of 2.5 hours after consumption (but symptoms can occur anywhere from 1 to 90 hours later.)
Some people also experience nausea, vomiting or headaches. One telltale sign that you've been "escolared" is that stool contains oily droplets, possibly of a yellowish, orange or greenish/brown color. It could take up to two days until you feel better.
While some countries have banned the sale of escolar as the result of its digestive side effects, the U.S. has not. Rather, the FDA merely advises against the sale of escolar and politely requests that sellers inform potential buyers or consumers of the explosive diarrhea and abject misery they are likely to face if consuming it. Since I've never seen such a disclaimer on a sushi menu, something tells me this voluntary disclosure isn't actually happening…
• IBS and The Cheesecake Factory effect: Many of my patients with irritable bowel syndrome (IBS) believe themselves to be highly susceptible to food poisoning at restaurants. After all, they reason, why else do they constantly find themselves running to the bathroom before the meal is even finished due to an acute attack of diarrhea?
My vote goes to our old friend, the gastrocolic reflex – a normal physiological phenomenon in which stretching of the stomach walls and arrival of fat in the small intestine trigger forward-motion (peristalsis) throughout the intestines. The gastrocolic reflex is our digestive system's natural way of making room for what's coming down the pike once a new meal has commenced.
In normal digestion, the gastrocolic reflex is responsible for the occasional urge to defecate within an hour or so after a meal. A common feature of IBS, however, is a gastrocolic reflex that may occur rapidly or vigorously, even with small snacks. When you've got diarrhea-predominant IBS, then sometimes all it takes is a meal ever so slightly larger than your tummy has agreed to accept – or ever so fattier – and you've got a violent gastrocolic reflex that will have you running for the loo before you can flag down the waiter and yelp "check, please!"
[Read: Food Intolerance: Fact and Fiction.]
This is why restaurant meals can be problematic. Restaurant portions are usually substantially larger than what you're used to eating at home – even if you're not actually at The Cheesecake Factory. When dining out with friends, you may also order multiple courses – resulting in more food volume than you might normally eat.
Perhaps you had a drink at the bar – even just a club soda – while waiting to meet your party. All of these factors contribute to a relatively higher degree of stomach stretch than that produced by, say, your typical Lean Cuisine. And since fats like butter and oil make food taste good, restaurants use them liberally in their dishes. Once that fat starts arriving in the small intestine – which can easily be within 30 minutes of starting the meal – there's always a chance that you may trigger a forceful gastrocolic reflex.
To be clear, plenty of people with IBS can and do enjoy restaurant meals without incident. And there are ways to prevent or minimize the likelihood of an attack when dining out – such as with antispasmodic medication or supplemental peppermint oil. But if you find yourself ending too many restaurant meals in the bathroom, don't be so quick to blame the place's sanitation.
• OK, so maybe it was food poisoning: Of course, foodborne illness remains a problem – and it's quite possible that it was responsible for your restaurant meal gone awry.
If you feel nauseous or start vomiting within 30 minutes of (and up to six hours after) a meal, especially one containing starchy foods and rice in particular, you're probably suffering from Bacillus cereus poisoning. A related strain of B. cereus causes cramps and watery diarrhea that sets in six to 15 hours after eating. This type of infection usually comes and goes within a day.
Another culprit for rapid-onset symptoms – within one to seven hours after a meal – is Staphylococcus auerus. S. auerus moves through you like a tornado – it's an intensely miserable but brief episode of nausea, vomiting, cramps and/or diarrhea that may last only a few hours or, at most, a day. Likely sources include egg-based foods (egg salad, mayo-based salads, custard or cream-filled pastries), poultry, meat or dairy products that have been improperly refrigerated.
[Read: How to Avoid Food Poisoning.]
If symptoms of diarrhea, stomach pain, nausea and vomiting start about six hours after a meal but take closer to a week to resolve, there's a good chance you're looking at salmonella poisoning. Salmonellosis affects 1.2 million Americans annually. It kicks in six to 72 hours after consuming food infected with a strain of salmonella bacteria, such as eggs, poultry, meat, fish, raw produce contaminated with sewage water and even dry goods like spices (including black pepper), nuts and chocolate.
High fever, lethargy, headache and possibly even a rash in addition to gastrointestinal symptoms characterize a rare and serious type of salmonellosis called typhoid fever. Typhoid fever is a serious health condition that warrants urgent medical attention. Symptoms, however, generally don't onset for one to three weeks after exposure to the bacteria.
[Read: New Hope for a Nasty Gut Bug.]
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Tamara Duker Freuman, MS, RD, CDN, is a registered dietitian whose NYC-based clinical practice specializes in digestive disorders, Celiac Disease, and food intolerances. Her personal blog, www.tamaraduker.com, focuses on healthy eating and gluten-free living.