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Your shrimp arrives at the table. You’re salivating, ready to dive in. But then your gaze narrows in on the thin black line along the backs of each shellfish. As you’re about to rip into some prawns, the thought of “is that…shrimp poop?” and, perhaps more importantly, “is it okay for you to eat it?” passes you by.
The thought of eating poopy seafood makes me sick, but I didn’t want to give up shrimp just yet. I wanted to talk to food safety experts to find out what was really going on. Is that dark line really what it looks like? If so, should you be worried about eating it? Read on to find out what experts say.
Shrimp is a popular shellfish enjoyed around the world. Many people love the delicious, sweet flavor of shrimp and how versatile it is to cook with. However, some people report having to make more frequent trips to the bathroom after eating shrimp. So does eating shrimp really make you poop? Let’s take a closer look at the evidence.
Why Shrimp May Cause Digestive Issues
There are a few reasons why shrimp could cause digestive upset
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High Fat Content – Shrimp contains a decent amount of fat, especially saturated fat. Too much fat at one time can overwhelm the digestive system and cause diarrhea.
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Allergies – Some people are allergic to shellfish like shrimp. An allergic reaction can cause inflammation in the digestive tract, resulting in diarrhea and other GI issues.
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Chitin – The shells of shrimp contain chitin, a fibrous compound that humans cannot digest properly For some people, undigested chitin acts as an irritant in the intestines and causes diarrhea.
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Bacterial Contamination – Raw or undercooked shrimp may contain bacteria like Salmonella and E. coli that can lead to food poisoning. Diarrhea is a common symptom of foodborne illnesses.
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Individual Sensitivity – Some people’s digestive systems are more sensitive and prone to diarrhea after eating high-fat foods like shrimp. The high osmolarity of shrimp may also draw more water into the intestines.
So in people with allergies, sensitivities, or weak digestion, shrimp does seem to commonly cause loose stools or diarrhea. But what does the science actually say?
Scientific Research on Shrimp and Diarrhea
Surprisingly, there isn’t much research specifically looking at shrimp’s laxative effects. However, several studies provide clues:
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A study in rats found that chitin from shrimp shells increased stool weight and moisture, suggesting a laxative effect.
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Another rat study showed that a diet containing 10% shrimp shells increased stool frequency and caused loose stools.
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A case report described diarrhea in a man after eating shrimp infected with a microsporidian parasite.
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Some small studies also found high rates of diarrhea and foodborne illnesses from raw or undercooked shrimp contaminated with bacteria like E. coli.
So while minimal, the current research suggests that shrimp shells, fat content, and potential bacteria may contribute to loose stools, diarrhea, or intestinal upset in some individuals. But more studies are still needed for definitive answers.
Tips to Minimize Digestive Issues from Shrimp
If you experience diarrhea or urgent bowel movements after eating shrimp, try these simple tips:
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Devein properly – Removing the digestive tract or “vein” from shrimp minimizes irritating chitin and digestive enzymes.
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Cook thoroughly – Cooking shrimp to an internal temperature of 145°F kills harmful bacteria that could cause food poisoning.
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Limit portion size – Stick to 4-6 oz of shrimp in a meal, as large portions may be hard to digest.
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Remove shells – Peeling shrimp removes the chitinous shells. Opt for peeled, deveined shrimp if the shells irritate your stomach.
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Choose lower fat options – Try grilled, steamed, or boiled shrimp instead of breaded and fried.
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Stay hydrated – Drink plenty of water and fluids when eating shrimp to aid digestion and prevent dehydration from potential diarrhea.
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Take probiotics – Probiotic supplements can help improve digestion of shrimp and reduce side effects like diarrhea.
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Avoid if allergic – Don’t eat shrimp if you have a shellfish allergy, as this often causes GI symptoms.
Making a few simple tweaks to how you select, prepare, and consume shrimp can often prevent or minimize urgent trips to the bathroom afterwards. But as with any food, your body’s response can vary. So take note of how you feel and adjust your diet accordingly.
When to See a Doctor
In most cases, shrimp-induced diarrhea is short-lived and not a major concern. However, contact your doctor if you experience:
- Severe abdominal pain or cramps
- Bloody stool
- Fever over 101°F
- Dehydration from fluid loss
- Diarrhea lasting over 3 days
These could be signs of a more serious condition like food poisoning, IBS, or infectious diarrhea requiring treatment. Your doctor can run tests to identify the cause and provide appropriate care.
They may also refer you to a dietitian to test for food allergies or sensitivities if shrimp frequently upsets your stomach. Getting to the root of GI issues can help prevent disruptive symptoms going forward.
The Bottom Line
Does shrimp make you poop? For some people, yes – components in shrimp like fat, chitin, and bacteria can irritate the digestive system and cause diarrhea in sensitive individuals. Proper cooking and preparation methods can often reduce this effect. But if shrimp frequently causes urgent bathroom trips, it may be best to limit your intake or avoid it altogether. Speak to your doctor for evaluating and managing ongoing diarrhea or GI issues after eating shrimp. With a few precautions, most people can enjoy the delicious taste of shrimp without the unpleasant side effects.
What’s that black line in shrimp?
The dark line running through the backs of shrimp goes by many names—the dorsal tract, back vein, or sand vein, Tori Stivers, MS, a seafood specialist at the University of Georgia Marine Extension and Georgia Sea Grant, tells SELF. The marking is made up of the shellfish’s stomach, midgut, and intestine. Those structures support the crustacean’s digestive process, so yes, that black stuff is the shrimp’s waste, she says.
As for what you’re actually seeing there? Shrimp are called bottom feeders for a reason: They munch on foods found in the muddy depths of the ocean, like plankton, worms, microscopic animals, and various types of organic debris like sand. So that black line is likely a combination of all those things in various stages of digestion, Dave Love, PhD, a senior scientist at the Johns Hopkins Center for a Livable Future, tells SELF.
Can eating shrimp’s poop make you sick?
Having established that the dark line is the shrimp’s intestines (okay, its poop), should you be afraid to eat it? It might look gross, but most people agree that it’s safe to eat as long as you cook it properly.
“Eating the shrimp’s digestive tract doesn’t make you sick—as long as you cook it thoroughly,” says Dr. Love. That means steaming, baking, frying, or whichever way you’re craving it, until it reaches 145°F. At this internal temperature, the shrimp will take on a firm texture.
That’s not to say you can’t get sick from eating shrimp in general. You can, but Dr. Paul says that eating shellfish raw or not cooked enough is usually what makes people sick. Love. For instance, just like ground beef, raw shrimp can contain bacteria like E. coli. But if you cook it all the way through, the heat will kill the bacteria and any other pathogens that could be harmful before they can mess up your digestive tract. So if you want to eat shrimp with the vein still in it, you might want to avoid raw shrimp sashimi and instead try them in a curry, stir-fry, garlicky pasta, or zesty taco.
Is the vein in shrimp poop?
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