Table of ContentsView AllTable of ContentsSigns and SymptomsTreatmentDiagnosisRepeat Infections
Table of ContentsView All
View All
Table of Contents
Signs and Symptoms
Treatment
Diagnosis
Repeat Infections
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Intestinal Worms: How Do You Know You Have Them?
Intestinal worms are most common in lower-income countries. The symptoms of intestinal worms may vary based on the worm. Often, people will have no symptoms of an intestinal worm infection.
Types of Intestinal WormsSeveral types of intestinal worms can infect humans. The general term for these animals is helminths. Several helminths, such as the following, cause illnesses:Roundworms (nematodes): This group includesAscarislumbricoides,threadwormsrhabditid nematode (Strongyloides stercoralis), which causesstrongyloidiasis, andpinworms(Enterobius vermicularis)—the most common intestinal worms in the United States.Hookworms(Ancylostoma duodenaleandNecator americanus):Hookwormsare the second most common helminthic infection in the United States.Whipworm(Trichuris trichiura): These worms take the shape of a whip and are wider at one end.Flatworms(platyhelminths) andtrematodes(flukes): This group includestapewormsand species that causeschistosomiasis.Thorny-headed worms(acanthocephalans): Infections of humans with these parasites are rare and typically asymptomatic.
Types of Intestinal Worms
Several types of intestinal worms can infect humans. The general term for these animals is helminths. Several helminths, such as the following, cause illnesses:Roundworms (nematodes): This group includesAscarislumbricoides,threadwormsrhabditid nematode (Strongyloides stercoralis), which causesstrongyloidiasis, andpinworms(Enterobius vermicularis)—the most common intestinal worms in the United States.Hookworms(Ancylostoma duodenaleandNecator americanus):Hookwormsare the second most common helminthic infection in the United States.Whipworm(Trichuris trichiura): These worms take the shape of a whip and are wider at one end.Flatworms(platyhelminths) andtrematodes(flukes): This group includestapewormsand species that causeschistosomiasis.Thorny-headed worms(acanthocephalans): Infections of humans with these parasites are rare and typically asymptomatic.
Several types of intestinal worms can infect humans. The general term for these animals is helminths. Several helminths, such as the following, cause illnesses:
Stool Signs
If you have an intestinal worm infection, you may be able to see worms or parts of worms (common with tapeworms in your stool.)Eggs and larvae are harder to see. If you see something in your stool that looks like a worm, bring it to a healthcare provider for diagnosis.
The worms all look different:
You may have gastrointestinal (GI) symptoms that change the look of your stool, making it more watery, mucousy, or even bloody. For example, chronic schistosomiasis and heavy hookworm infections may lead to blood in the stool.
A severe whipworm infection can cause frequent, painful bowel movements of mucus, water, and blood.
GI Symptoms
Most intestinal worms do not cause symptoms if the infection is light. Gastrointestinal symptoms from heavier infections with intestinal worms can include the following:
Non-GI Symptoms
While intestinal worms live in the gut and cause symptoms there, there are other symptoms to be aware of if you’re worried you have these parasites. Some of the most common non-GI signs and symptoms of intestinal worms include the following:
Non-gastrointestinal symptoms that may show up with intestinal worm infections include the following:
Being Asymptomatic
Often, people who are otherwise healthy with mild infections and few worms are typically asymptomatic—they usually will not have symptoms of intestinal worms.
Common intestinal worm parasites that are often asymptomatic include:
Treatment to Get Rid of Intestinal Worms
If you find intestinal worms in your poop, mention it to a healthcare provider. In healthy people, intestinal worms typically go away without treatment.
If you need treatment to deworm your body, most soil-transmitted helminth parasites respond to a single 400 milligram (mg) dose of Albenza (albendazole) or a 500 mg tablet of Vermox (mebendazole).
Infections with strongyloidiasis respond well to Stromectol (ivermectin) treatment.
Pinworm infection is treated with Albenza, Vermox, or Ascarel (pyrantel pamoate). All infested family members should take the drugs at the same time. It is given in two doses—the second dose two weeks after the first.
Intestinal schistosomiasis is treated with one to two days of prescription Biltricide (praziquantel).
Intestinal Worm Diagnosis Process
If you think you have intestinal worms, a healthcare provider will take a health history and review your hygiene and recent travel to endemic areas.
The only way to diagnose intestinal worm parasites is to see eggs, larvae, or adult worms in the stool or collect eggs from the perineum in the case of pinworms.
The fecal (stool) exam, also called an ova and parasite test, detects the presence of intestinal worms and other gut parasites. For the test, you’ll need to provide three or more stool samples collected on separate days.
To collect the samples, you may need special containers with preservative fluid. If you don’t use a special cup with fluid, keep the samples refrigerated but not frozen.
Generally, when doing a stool sample test for intestinal worms, remember to:
Additional tests that may be used to diagnose intestinal worms or rule out other intestinal parasites include:
To find a female worm, look around the anal area or in pajamas about two to three hours after falling asleep. If the worm is out, you’ll see it with the naked eye. It is between 1/4- and 1/2-inch long.
If you don’t see the worm, you should do a tape test as soon as you wake up in the morning, before washing, bathing, going to the toilet, or getting dressed.
Firmly press a piece of transparent tape against the folds of skin around the anus. The tape will pick up eggs or worms on the perineum. Repeat this for three days in a row. You’ll need to seal the tape in a plastic bag and take it to your healthcare provider, who can have the lab look at it under a microscope.
It’s also possible that you could find pinworm eggs in samples taken from under the fingernails.
Repeat Infection From Intestinal Worms
Helminths live in the soil or the environment. They may pass through the skin or enter the intestines through something you eat or drink. They can even be breathed in.
For example, hookworm eggs hatch in the soil and attach to bare feet and ankles. They penetrate the skin, migrate around the body, and end up in the intestine, where they attach to the lining and gorge on blood.
Threadworms get into the body through the skin from contaminated soil, but their eggs hatch in the intestine.
If you find yourself repeatedly getting infections with soil-based intestinal worms, there are some steps you can take to decrease your risk:
Raw MeatAvoid eating raw or uncooked pork or beef. Tapeworms live in the flesh of cows and pigs.
Raw Meat
Avoid eating raw or uncooked pork or beef. Tapeworms live in the flesh of cows and pigs.
To decontaminate and avoid reinfection with pinworm during and after treatment, the entire household must take precautions to reduce the spread of the pinworm eggs:
Pinworm SourcesPinworms can live up to two or three weeks at room temperature, so it’s possible to be reinfected after deworming the entire house.Pinworms spread from the bare anal area to the hands or fingernails, then onto surfaces. They spread quickly when:Kids scratch their anus and touch playmates or toys, spreading eggs.Eggs spread to clothing or bedding and then spread around the home.Eggs are swept into the air and breathed into the mouth.Eggs drop onto food and are eaten.
Pinworm Sources
Pinworms can live up to two or three weeks at room temperature, so it’s possible to be reinfected after deworming the entire house.Pinworms spread from the bare anal area to the hands or fingernails, then onto surfaces. They spread quickly when:Kids scratch their anus and touch playmates or toys, spreading eggs.Eggs spread to clothing or bedding and then spread around the home.Eggs are swept into the air and breathed into the mouth.Eggs drop onto food and are eaten.
Pinworms can live up to two or three weeks at room temperature, so it’s possible to be reinfected after deworming the entire house.Pinworms spread from the bare anal area to the hands or fingernails, then onto surfaces. They spread quickly when:
If pinworm reinfection continues, consider if other playmates, schoolmates, or close contacts outside the home may be re-introducing the eggs. Ensure everyone infected—even those outside the home—gets the two-dose treatment and decontaminates their environment.
Summary
Parasitic intestinal worms include roundworms, pinworms, hookworms, and tapeworms. These worms infect humans and can cause various illnesses.
Symptoms range from gastrointestinal issues like diarrhea and abdominal pain to changes in stool appearance. You may also see parts of a worm in your stool or changes in stool appearance. Non-gastrointestinal symptoms of intestinal worms include rashes, respiratory problems, anemia, and malnutrition.
Diagnosis involves stool sample testing to look for worms, eggs, or larvae. The healthcare professional may run other tests depending on the worm. Treatment includes medicines.
Prevention strategies include maintaining hygiene, cooking food properly, and avoiding contaminated water sources.
21 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Unlimit HealthSoil-transmitted helminthiases.Centers for Disease Control.ParasitesCenters for Disease Control and Prevention.Strongyloidiasis.Centers for Disease Control.Pinworm infection.American Academy of Family Physicians.Common intestinal parasites.Mathison BA, Mehta N, Couturier MR.Human acanthocephaliasis: a thorn in the side of parasite diagnostics.J Clin Microbiol. 2021;59(11):e0269120. doi:10.1128/JCM.02691-20Centers for Disease Control and Prevention.Symptoms of human tapeworm.Centers for Disease Control and Prevention.Ascariasis.UK National Health Service.Worms in humans.Centers for Disease Control and Prevention.Schistosomiasis.Centers for Disease Control and Prevention.Intestinal hookworm.Centers for Disease Control and Prevention.Whipworms.World Health Organization.Soil-transmitted helminth infections.The Task Force for Global Health.Intestinal worms.Kpene G, Lokpo S, Deku J, Agboli E, Owiafe P.Asymptomatic intestinal parasitic infestations among children under five years in selected communities in the ho municipality, ghana.Ethiop J Health Sci. 2020;30(6):867-874. doi:10.4314/ejhs.v30i6.3Centers for Disease Control and Prevention.Clinical overview of schistosomiasis.Centers for Disease Control and Prevention.Diagnosis of parasitic diseases.MedlinePlus.Ova and parasite test.New York State Department of Health.Pinworm InfectionCenters for Disease Control and Prevention.Pinworm infection.New York State Department of Health.Pinworm Infection
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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Unlimit HealthSoil-transmitted helminthiases.Centers for Disease Control.ParasitesCenters for Disease Control and Prevention.Strongyloidiasis.Centers for Disease Control.Pinworm infection.American Academy of Family Physicians.Common intestinal parasites.Mathison BA, Mehta N, Couturier MR.Human acanthocephaliasis: a thorn in the side of parasite diagnostics.J Clin Microbiol. 2021;59(11):e0269120. doi:10.1128/JCM.02691-20Centers for Disease Control and Prevention.Symptoms of human tapeworm.Centers for Disease Control and Prevention.Ascariasis.UK National Health Service.Worms in humans.Centers for Disease Control and Prevention.Schistosomiasis.Centers for Disease Control and Prevention.Intestinal hookworm.Centers for Disease Control and Prevention.Whipworms.World Health Organization.Soil-transmitted helminth infections.The Task Force for Global Health.Intestinal worms.Kpene G, Lokpo S, Deku J, Agboli E, Owiafe P.Asymptomatic intestinal parasitic infestations among children under five years in selected communities in the ho municipality, ghana.Ethiop J Health Sci. 2020;30(6):867-874. doi:10.4314/ejhs.v30i6.3Centers for Disease Control and Prevention.Clinical overview of schistosomiasis.Centers for Disease Control and Prevention.Diagnosis of parasitic diseases.MedlinePlus.Ova and parasite test.New York State Department of Health.Pinworm InfectionCenters for Disease Control and Prevention.Pinworm infection.New York State Department of Health.Pinworm Infection
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Unlimit HealthSoil-transmitted helminthiases.Centers for Disease Control.ParasitesCenters for Disease Control and Prevention.Strongyloidiasis.Centers for Disease Control.Pinworm infection.American Academy of Family Physicians.Common intestinal parasites.Mathison BA, Mehta N, Couturier MR.Human acanthocephaliasis: a thorn in the side of parasite diagnostics.J Clin Microbiol. 2021;59(11):e0269120. doi:10.1128/JCM.02691-20Centers for Disease Control and Prevention.Symptoms of human tapeworm.Centers for Disease Control and Prevention.Ascariasis.UK National Health Service.Worms in humans.Centers for Disease Control and Prevention.Schistosomiasis.Centers for Disease Control and Prevention.Intestinal hookworm.Centers for Disease Control and Prevention.Whipworms.World Health Organization.Soil-transmitted helminth infections.The Task Force for Global Health.Intestinal worms.Kpene G, Lokpo S, Deku J, Agboli E, Owiafe P.Asymptomatic intestinal parasitic infestations among children under five years in selected communities in the ho municipality, ghana.Ethiop J Health Sci. 2020;30(6):867-874. doi:10.4314/ejhs.v30i6.3Centers for Disease Control and Prevention.Clinical overview of schistosomiasis.Centers for Disease Control and Prevention.Diagnosis of parasitic diseases.MedlinePlus.Ova and parasite test.New York State Department of Health.Pinworm InfectionCenters for Disease Control and Prevention.Pinworm infection.New York State Department of Health.Pinworm Infection
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Centers for Disease Control.Parasites
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Centers for Disease Control and Prevention.Symptoms of human tapeworm.
Centers for Disease Control and Prevention.Ascariasis.
UK National Health Service.Worms in humans.
Centers for Disease Control and Prevention.Schistosomiasis.
Centers for Disease Control and Prevention.Intestinal hookworm.
Centers for Disease Control and Prevention.Whipworms.
World Health Organization.Soil-transmitted helminth infections.
The Task Force for Global Health.Intestinal worms.
Kpene G, Lokpo S, Deku J, Agboli E, Owiafe P.Asymptomatic intestinal parasitic infestations among children under five years in selected communities in the ho municipality, ghana.Ethiop J Health Sci. 2020;30(6):867-874. doi:10.4314/ejhs.v30i6.3
Centers for Disease Control and Prevention.Clinical overview of schistosomiasis.
Centers for Disease Control and Prevention.Diagnosis of parasitic diseases.
MedlinePlus.Ova and parasite test.
New York State Department of Health.Pinworm Infection
Centers for Disease Control and Prevention.Pinworm infection.
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