Can Eating Poop Make You Sick? Causes and What to Do

Eating feces, whether accidentally or intentionally, can absolutely make you sick. Human and animal stool carries bacteria, viruses, and parasites that cause illnesses ranging from mild diarrhea to severe, life-threatening infections. The risk depends on whose stool it is, what pathogens it contains, and how much is ingested, but even trace amounts can transmit certain organisms. Understanding the specific dangers, how exposure actually happens, and what steps to take afterward matters because contact with fecal matter is far more common than most people realize.

What Is Actually in Feces That Makes You Sick

Stool is not just waste food. It contains billions of microorganisms per gram, including bacteria, viruses, fungi, and sometimes parasites. Most of the bacteria in a healthy person’s gut are harmless or even beneficial when they stay inside the intestinal tract. The problem is that feces also commonly carries pathogens that cause disease when they enter the mouth or are swallowed. Researchers testing community water sources contaminated by human waste have identified diarrheal pathogens including rotavirus, adenovirus, Vibrio cholerae, pathogenic Escherichia coli, Cryptosporidium, and Giardia.¹

Animal feces introduces additional risks. A systematic review of research on animal fecal exposure found that roughly one-third of deaths among children under five from diarrheal disease globally are attributed to pathogens found in animal stool. Campylobacter infection was especially common among children living near poultry, due to direct contact with chicken droppings. People with household pets were over two and a half times more likely to be infected with certain strains of Giardia compared to those without pets.²

The short list of common fecal pathogens includes bacteria like Salmonella, Shigella, Campylobacter, and E. coli O157; viruses like rotavirus, norovirus, and hepatitis A; and parasites like Giardia, Cryptosporidium, and Entamoeba. Any of these can produce symptoms ranging from watery diarrhea and cramping to bloody stool, fever, dehydration, and in vulnerable people, organ damage or death.

How Little It Takes

One of the most unsettling aspects of fecal-oral transmission is how tiny the infectious dose can be for certain organisms. A review of infectious dose data from volunteer feeding studies found enormous variation by pathogen. Salmonella and most E. coli strains required large numbers of organisms to cause illness (over 100,000), but Shigella species could cause infection with fewer than 10 organisms. Campylobacter jejuni caused illness with as few as 500 organisms, and Cryptosporidium parvum could infect with just 10 oocysts. Entamoeba coli could do it with a single cyst.³

What this means practically is that for the most infectious organisms, a quantity of feces invisible to the naked eye can be enough to make someone sick. You do not need to eat a visible amount. A smear on a hand, a contaminated surface touched before eating, or a splash of contaminated water can deliver enough organisms to cause disease. The infectious dose also varies with the person: children, elderly adults, and people with weakened immune systems tend to get sick from smaller exposures.

How Fecal Exposure Actually Happens

Most people picture fecal exposure as something extreme and obvious, but the reality is far more mundane. A systematic review and meta-analysis of hand contamination studies found that E. coli was present on hands in about 62% of samples across study populations, and fecal coliform bacteria were found in about 66% of samples. These studies confirmed that hands serve as a bridge connecting sources of fecal contamination like soil, floors, and drains to the mouth.⁴

Common routes of accidental fecal ingestion include:

• Contaminated hands: After using the toilet, changing diapers, handling animals, or touching contaminated surfaces, bacteria transfer to food or directly to the mouth.
• Contaminated water: Drinking or swimming in water polluted with sewage or animal waste.
• Food contamination: Produce irrigated with contaminated water, or food prepared by someone with poor hand hygiene.
• Environmental surfaces: Doorknobs, toys, playground equipment, and bathroom fixtures can harbor fecal bacteria for hours or days.

The fact that fecal bacteria are found on the majority of hands tested globally underscores a point that public health researchers have emphasized for decades: fecal-oral transmission is not a rare, dramatic event. It is an everyday risk managed primarily by hand hygiene.

Children Are Especially Vulnerable

Young children face the highest risk of fecal ingestion for a simple reason: they put everything in their mouths. Infants and toddlers explore the world orally, and in environments where animal or human feces is present on the ground, on objects, or on hands, direct mouthing of fecal matter happens more often than parents might expect. A prospective study of young children in the Democratic Republic of the Congo tracked the health effects of observed mouthing behaviors. Children who were seen putting feces or feces-contaminated objects into their mouths experienced a significant drop in height-for-age over six months, indicating that the repeated exposure was not just causing acute illness but also impairing growth.⁵

This growth impairment reflects a condition researchers call environmental enteric dysfunction, where chronic low-level exposure to fecal pathogens damages the gut lining and impairs nutrient absorption. It is not dramatic food poisoning with vomiting and diarrhea, though that happens too. It is a quieter, longer-term consequence of living in an environment where fecal contamination is difficult to avoid. For families in settings with limited sanitation, childproofing strategies like keeping children off contaminated floors and penning animals away from play areas can make a meaningful difference.

When Adults Eat Feces Intentionally

Coprophagia, the deliberate eating of feces, is rare in adults but does occur. It has been documented in association with several psychiatric and neurological conditions, including schizophrenia, dementia, intellectual disability, obsessive-compulsive disorder, depression, and delirium.⁶ Case studies of people with schizophrenia suggest that the behavior often stems from fixed delusional beliefs, such as a conviction that eating feces provides health benefits or serves as a form of self-punishment driven by delusional guilt.⁷

The medical risks for people with coprophagia are serious. Repeated ingestion of feces exposes the person to all the pathogens discussed above on an ongoing basis, compounded by the fact that their underlying conditions often make them less able to report symptoms or seek care. Treatment typically targets the underlying psychiatric condition, and adequate antipsychotic response has been shown to resolve the behavior in some cases. Behavioral interventions, including techniques that redirect the person toward alternative behaviors in situations where coprophagia normally occurs, have also been shown to reduce the behavior effectively.⁸

What to Do After Accidental Ingestion

If you or your child accidentally ingests feces, the response depends on the amount and the circumstances. For a small, incidental exposure like a toddler touching a soiled diaper and then putting fingers in their mouth, the immediate steps are straightforward: rinse the child’s mouth with water, wash hands and face thoroughly with soap, and watch for symptoms over the next few days. Most single small exposures in healthy people do not result in illness.

If a larger amount is involved, or if the person is immunocompromised, very young, or elderly, contacting a healthcare provider promptly makes sense even before symptoms appear. The main symptoms to watch for are diarrhea (especially watery or bloody), vomiting, fever, and abdominal cramping. These typically appear within one to three days for bacterial infections, though some parasites and viruses have longer incubation periods.

When symptoms do develop, the most important immediate concern is dehydration, particularly in children. Oral rehydration with water and electrolytes should start at the first sign of diarrhea or vomiting. A doctor can order stool tests that check for bacteria, viruses, parasites, and markers of gut inflammation to identify the specific pathogen and guide treatment.⁹ Some infections, like those caused by C. difficile, require specific laboratory testing protocols to diagnose accurately.¹⁰

Antibiotics are not always the right response. Many fecal-oral infections are viral or parasitic and will not respond to antibiotics, and some bacterial diarrheal illnesses resolve on their own. In fact, treating certain E. coli infections with antibiotics can worsen outcomes. A healthcare provider can determine whether antibiotic or antiparasitic treatment is warranted based on the pathogen involved.

Handwashing Is Not Just Advice, It Is the Primary Defense

Given how frequently hands carry fecal bacteria, handwashing is the single most effective barrier against fecal-oral disease transmission. A study comparing hand contamination before and after washing found that bacteria of potential fecal origin were present on 44% of unwashed hands. Washing with water alone dropped that to 23%. Washing with plain soap and water brought it down to 8%.¹¹ The soap does not need to be antibacterial; regular soap works by physically lifting bacteria off the skin and into the rinse water.

In healthcare settings, systematic handwashing monitoring has been associated with about a 30% reduction in the transmission of infectious agents.¹² The key moments for handwashing are after using the toilet, after changing diapers, after handling animals or cleaning up pet waste, and before preparing or eating food. For parents of toddlers, frequent hand-cleaning during play, especially outdoors or in areas where animals are present, can substantially reduce the risk of fecal pathogen ingestion.

Occupational Risks for People Who Handle Feces

Some people encounter fecal matter as part of their work. Sanitation workers, sewer maintenance crews, farm laborers, and healthcare workers all face elevated fecal exposure. A systematic review and meta-analysis of health outcomes among sanitation workers found consistent evidence of increased risk for gastroenteritis and respiratory conditions. The pooled risk for hepatitis A, the only outcome with enough data for formal meta-analysis, was about twice as high in sanitation workers compared to the general population.¹³

Farm workers handling animal stool face their own specific risks. Research measuring actual fecal ingestion rates among ruminant farm workers found that workers inadvertently ingested small amounts of fecal matter daily, with estimates averaging around 7 to 9 milligrams per day depending on the season. Risk assessments based on these numbers found that beef cattle stool posed the highest risk for E. coli O157 infection compared to stool from other ruminants.¹⁴ Protective equipment, proper hygiene facilities, and workplace protocols are essential in these settings but are not always available, especially in lower-income countries where much of this work takes place.

Fecal Transplants and Why They Are Different

If eating feces is dangerous, the existence of fecal microbiota transplantation, commonly known as FMT, might seem contradictory. In FMT, processed stool from a carefully screened donor is introduced into a patient’s gut, usually to treat recurrent C. difficile infection. The procedure works because it repopulates the intestinal tract with a healthy community of microbes that can outcompete the pathogen.

The critical difference is screening. Donors undergo extensive testing for infectious diseases and drug-resistant organisms before their stool is accepted. Even with these precautions, serious adverse events have been linked to FMT products, particularly when screening protocols did not include testing for multi-drug resistant organisms.¹⁵ Known risks include infection, transmission of resistant bacteria, and aspiration if the material is delivered through a nasal or oral tube.¹⁶

The rise of do-it-yourself FMT videos and guides online is concerning precisely because they bypass the rigorous donor screening that makes clinical FMT relatively safe. Swallowing unscreened feces from anyone, even a healthy-seeming person, carries all the risks outlined in this article and more. A person can be an asymptomatic carrier of hepatitis, C. difficile, drug-resistant bacteria, or parasites without showing any signs of illness. Clinical FMT exists as a tightly controlled medical procedure for good reason.

Coprophagy in the Animal Kingdom

Humans are unusual in that eating feces is almost always harmful for us, but many animals do it routinely with real biological benefits. Rabbits eat their own soft cecal pellets to absorb nutrients that were not fully extracted during the first pass through the digestive tract. Dung beetles build their entire life cycle around feces. And in at least one mammal, fecal ingestion serves a fascinating hormonal purpose.

Naked mole-rats live in large underground colonies with a single breeding queen. Researchers discovered that when subordinate females ate feces from a pregnant queen, they became more attentive to pups. The queen’s feces during pregnancy contains elevated levels of estradiol, a hormone that stimulates parental care behaviors. When scientists fed subordinate females food pellets supplemented with estradiol, the same behavioral change occurred, confirming that the hormone in the feces was driving the effect. Feces from non-pregnant queens, without the estradiol boost, did nothing beyond providing nutrition.¹⁷

These examples from the animal world illustrate that the danger of fecal ingestion is not inherent to feces itself but depends on the organisms and substances it contains and on the species doing the eating. Humans lack the specialized gut adaptations that allow many animals to safely consume feces, and our feces tends to carry a pathogen load shaped by our diet, our microbial community, and our diseases.

Historical Uses of Feces in Medicine

The idea of using feces therapeutically is not new. In the classical Greco-Roman world, rationalistic medicine, including practitioners as prominent as Galen, made therapeutic use of excrement and urine. Popular medicine at the time appears to have done so on an even larger scale.¹⁸ Traditional medical systems in various cultures have continued similar practices into the modern era. In Laos, for instance, elephant feces has been used in traditional medicine for gastrointestinal and skin problems, prepared as drinks or external lotions. Practitioners attribute the therapeutic value to the medicinal plants that elephants consume, fragments of which remain in the dung.¹⁹

These historical practices are worth knowing about because they show that FMT did not emerge from nowhere; the intuition that gut microbes from a healthy individual could benefit a sick one has ancient roots, even if the mechanism was misunderstood. They also serve as a reminder that without modern screening and processing, using feces as medicine carries the same infection risks that make accidental ingestion dangerous. The ancient world did not have germ theory, and people undoubtedly got sick from these treatments even as some may have benefited in ways we cannot fully evaluate today.