What to blame for your stomach bug?

It happens like a bolt out of the blue. One minute you’re fine, and the next you begin to sweat as crippling cramps move wavelike through your belly. You vomit or have diarrhoea, or both, fearing you won’t live to see another day. And then it goes away. You’re back to your old self, maybe after a day or two of binge-watching Netflix, chasing dry crackers with ginger ale.

The Centre for Disease Control and Prevention estimates this scenario, known as an “acute gastrointestinal event,” happens to all of us at least once a year. The bouts, while extremely unpleasant, usually don’t occasion a trip to the doctor or require any medication.

But such events tend to make us spin our gears trying to pinpoint what made us so miserably sick. While it’s hard to know for sure, there are clues that might help you determine the source and reduce your risk in the future. “People tend to blame the last thing they ate, but it’s probably the thing before the last thing they ate,” said Dr Deborah Fisher, a gastroenterologist and associate professor at Duke University School of Medicine.

It takes the stomach around four to six hours to empty a full meal, and then the small intestine takes about six to eight hours to squeeze out all the nutrients and empty into the colon. The remains linger there for another one to three days, fermenting and being formed into what ultimately is flushed down the toilet. The so-called bowel transit time varies significantly from person to person, but gastroenterologists said you can easily find out what’s normal for you by eating corn and watching for when the indigestible kernels appear in your stool.

Gross, perhaps, but with that baseline, the next time you get sick, you’ll be better able to estimate when you might have eaten the offending meal. For example, if you throw up something and don’t have diarrhoea or roiling further down, it could be that what made you ill was so­mething you ate within the last four to six hours. If you wake up in the middle of the night with cramps and diarrhoea, it’s more likely something you consumed a good 18 to 48 hours earlier, depending on the results of your corn test.

Most food-borne illnesses are caused by viruses or bacteria, such as norovirus, Staphylococcus aureus, campylobacter, salmonella, E coli and Bacillus cereus. So in addition to figuring out the correct time-frame of consumption, also consider what foods are more likely to be contaminated. Items cited frequently on the Food and Drug Administration’s food recall list include leafy greens, culinary herbs, melons with textured surfaces like cantaloupe, fresh tomatoes, cucumbers, jalapeño peppers, nut butters, shellfish, frozen peas, cheese and ice cream.

Also suspicious are any foods left out for several hours, like the classic potato salad at the family picnic or fried rice at a Chinese buffet.

Restaurant food tends to be riskier in general not only because more hands are involved in the preparation but also because the ingredients are ordered in bulk. “A fast-food hamburger could have meat from a hundred different cows,” Fisher said, and it takes only one with a pathogen to make you sick. “The eggs in your two-egg omelette were poured out of a carton so it could have come from 50 different chickens,” she said.

Similarly suspect are freshly made juices and smoothies which are extracted from pounds and pounds of produce. Just one speck of contaminated dirt in your detox drink could upend your gut. And think of all the hands that necessarily touched the produce from the time it was picked in the field to when it was chopped and crammed into the Vitamix.

Let’s not forget about germs on your own hands if you’re not diligent about washing them with soap and water. Did you eat or otherwise put your fingers in your mouth after gripping the pole on the subway or after throwing a slobbery ball for your dog? Did you put your mobile phone down on the table at a coffee shop — or on top of the toilet-paper dispenser in a public restroom — and then put it up to your mouth to take a call? Germs that make it into your digestive tract don’t always come from food.

And sometimes your gut distress isn’t caused by a germ at all. It could be an overdose of fermentable oligosaccharides, disaccharides, monosaccharides and polyols, known in public health circles as Fodmaps. These are essentially carbohydrates that, eaten in excess, are not well absorbed in the small intestine and then make their way into your colon to cause all kinds of trouble. They include myriad things we’re encouraged to eat including broccoli, brussels sprouts, radicchio, asparagus, avocados, mushrooms, peaches, whole grains and legumes.

“People are trying to eat so healthy these days, but a lot of those things are high in Fodmaps,” said Dr Scott Gabbard, a gastroenterologist at the Cleveland Clinic. “You could always eat a lot of salad, but on that certain day, that certain combination of fruits and vegetables in your salad was just high enough in Fodmaps that it overrode your system’s capability to absorb those carbohydrates and you ended up with something almost like a purging.”
Gastrointestinal events
Drugs are also a common source of acute gastrointestinal events. Fisher mentioned the story of an otherwise healthy and active patient who had bouts of GI distress every few months or so. After many tests came back negative, she finally determined it was the ACE inhibitor he was taking to control his blood pressure.
“A side effect of the drug is that it causes swelling in the intestines so he would get these temporary, partial obstructions,” Fisher said. “He would vomit and skip a meal and then the swelling would go down. It went on and on until we took him off that drug and now he’s fine.”

Medications used to treat depression, allergies and gastrointestinal reflux can also make you more vulnerable to intense, short duration atta­cks of vomiting or diarrhoea, or both. Recreati­onal drugs could also be the culprit. “We’re starting to see more cyclic vomiting syndrome called cannabis hyperemesis because THC content of marijuana now is so high,” Gabbard said, referring to psychoactive component of marijuana.

Finally, there’s stress. What’s going on in your head has an enormous impact on your gut and vice versa. “The human brain and nervous system is very intimately mixed with another nervous system that is present in the walls of the intestine,” said D Santhi Swaroop Vege, a gastroenterologist at the Mayo Clinic.  

So instead of something that you ate, it could be you’ve swallowed your fear, anxiety, anger or sadness and it’s wreaking havoc on the nerves, chemical secretions and microbiota that keep your bowels operating smoothly. Gastroenterologists as well as psychiatrists said it’s not uncommon for acute gastrointestinal events to cease or become less frequent after a patient quits a bad job or leaves a bad relationship. That’s why, when making a difficult decision, you might just want to trust your gut.