Stool (poop) comes in many forms, colors, and consistencies. It may also give off different smells. All of these stool factors can tell you more about your health and help you figure out if you have certain medical conditions.
Specifically, poop that smells different could be a sign of digestive problems like inflammatory bowel disease (IBD). There are two main types of this disease, which causes painful and swollen digestive tracts: Crohn’s disease and ulcerative colitis.
Why does my body shake when I have a BM? May 1, 2024 by a member of the MyCrohnsAndColitisTeam
Tuna is a popular and nutritious food, but some people report that eating tuna makes their poop smell bad. What causes tuna to make poop smell, and is it actually the tuna’s fault?
Why Tuna Sometimes Causes Smelly Poop
There are a few reasons why tuna might be linked to foul-smelling stool:
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Tuna is high in protein and fat Protein and fat take longer to digest than carbs, allowing more time for odor-causing gut bacteria to act on them This produces smelly compounds like indoles, skatoles, and ammonia.
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Tuna contains sulfur-containing amino acids. Cysteine and methionine give tuna its distinct flavor. Sulfur compounds produce rotten egg-like odors in poop as they’re broken down by gut bacteria.
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Canned tuna contains added preservatives. Sulfite preservatives like sodium metabisulfite also contain sulfur, which can cause foul stool smells.
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Some people don’t digest protein efficiently. Conditions like lactose intolerance food allergies IBS, or IBD can impair protein digestion and absorption. More protein reaches the colon, fueling smelly bacteria activity.
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Tuna is a “test” food. Since tuna has a strong scent itself, it’s easy to notice if it affects your poop smell. People may assume tuna is the culprit when it’s actually something else they ate.
So while tuna itself does contain compounds that can cause stool to smell, it may not necessarily be the only or direct cause of foul odors.
Other Causes of Smelly Poop
Tuna gets blamed as a poop-stinker, but many other foods and factors can also make feces smelly:
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High-protein foods like meats, eggs, and dairy
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Cruciferous vegetables including cabbage, broccoli, and cauliflower
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Foods containing sulfur compounds like garlic, onions, asparagus
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Fruits like durian, jackfruit, pineapple, and citrus fruits
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High-fat, greasy, and fried foods which are harder to digest
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Artificial sweeteners like xylitol or sorbitol found in sugar-free foods
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Medications including antibiotics, laxatives, and supplements like iron
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Dehydration and stool consistency
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Gut infections from bacteria, viruses, or parasites
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Chronic digestive conditions like IBS, Crohn’s, celiac, and colitis
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Food intolerances and allergies to things like dairy, gluten, etc.
If you suspect certain foods make your poop smell, try an elimination diet to pinpoint the offenders. Stop eating the “suspicious” food for 1-2 weeks, then reintroduce it to see if smells return. A food diary can help too.
When Smelly Poop Needs Medical Attention
In most cases, foul-smelling stool is just a nuisance and not a medical concern. But if it’s accompanied by other symptoms, be sure to consult your doctor:
- Blood or mucus in stool
- Diarrhea lasting over 3 days
- Severe abdominal pain or cramping
- Unintentional weight loss
- Persistent nausea or vomiting
- Fever higher than 100.4°F (38°C)
These red flags can indicate an underlying condition like food poisoning, IBD, IBS, infections, or other issues needing treatment.
Normal, healthy stool does still stink a bit since it contains waste and gases produced by gut bacteria. But if odor is extremely foul or symptomatic of illness, take note.
Tips to Reduce Smelly Poop
To help minimize unpleasant poop odors:
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Stay hydrated to avoid dehydration and overly loose or hard stools
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Limit problem foods like dairy, cruciferous veggies, fatty goods
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Eat more fiber from fruits, veggies, whole grains to improve stool bulk
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Take probiotics to promote a healthy gut microbiome
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Choose low-odor proteins like plant-based options over meats
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Avoid overeating to prevent undigested food from reaching colon
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Use air fresheners or light candles in the bathroom
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Ventilate the bathroom by opening windows, turning on fans
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Clean the toilet bowl with chlorine or enzymatic cleaners
The Bottom Line
It’s true that tuna can be responsible for foul poop odors on occasion. But many other foods and factors often play a role too.
If smells are mildly annoying, diet tweaks and bathroom ventilation can help. But if you’re experiencing other troubling symptoms along with odor, see your doctor to rule out any underlying conditions needing treatment.
Types of Stool Smells
While stool never smells good, it can sometimes take on an even more unpleasant odor than usual. Your diet is the most common cause of bad-smelling stool.
In some cases, certain types of odors are a sign of a health condition. This can occur when organs stop working properly, raising the levels of smell-causing molecules in the body. A good example is that your digestive organs and the bacteria in your intestines break down the food you eat. Certain types of bacteria may create smelly substances as they digest food. Your liver also breaks these substances down, which gets rid of their smell, and your kidneys get rid of them from your body. Problems with these organs could lead to unpleasant smells in your stool.
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Stool (poop) comes in many forms, colors, and consistencies. It may also give off different smells. All of these stool factors can tell you more about your health and help you figure out if you have certain medical conditions.
Specifically, poop that smells different could be a sign of digestive problems like inflammatory bowel disease (IBD). There are two main types of this disease, which causes painful and swollen digestive tracts: Crohn’s disease and ulcerative colitis.
How Should A Healthy Poop Smell?
FAQ
Why does my stool smell like tuna?
Do you smell after eating tuna?
What is the most common cause of smelly stool?
Why is my poop sticky and smelly?
Why does my poop smell like fish?
Our poop can take on some pretty strange smells depending on what we eat or in relation to certain health conditions. If your bowel movements have started to smell like fish, here’s what you need to know. For one, it may mean that you’ve been loading up on seafood recently.
Is it safe to have tuna casserole for dinner if one has mild constipation?
Fish like tuna and white noodles do not have fiber, so, they will not make constipation worse, but they will not help to relieve it. Peas and vegetables contain fiber. So, try to prepare this dish with brown whole grain noodles, peas, and many vegetables. This way it will have a lot of fiber and will help with your condition.
Does poop smell bad?
Not exactly. “The way poop smells can indicate a wide variety of things,” Christine Lee, MD, a gastroenterologist at Cleveland Clinic, tells SELF. Most of the time, a foul scent alone isn’t indicative of anything worrisome.
Why does my poop smell so gnarly?
#TFW you drop a plop so gnarly you have to clutch your own pearls. While all poop smells, big swings in stank can be a reflection of recent lifestyle changes or a sign of something going on with your body. 1. Malabsorption Any number of conditions can cause your body to struggle to absorb enough nutrients.