White Worms in Stool: What They Mean

White worms in stool are most often pinworms, which the CDC describes as small, thin and white, about the size of a staple. Less often, a larger worm in the stool is a roundworm or a segment of a tapeworm, so the safest next step is to note what you saw, keep a sample if you can, and have a clinician confirm what it is before any treatment.

Seeing something move in the toilet is alarming, but it is usually not an emergency. This page explains what the common worms look like, what else can be mistaken for a worm, which tests confirm it, and when to get care in person. It is general education, not a diagnosis.

What do worms in human poop look like?

Different worms look very different. A rough guide, based on CDC and MedlinePlus descriptions:

| What you saw | What it may be | Notes | |---|---|---| | Tiny white threads, about the size of a staple, sometimes moving | Pinworm (Enterobius vermicularis) | Most often seen around the anus, on underwear or on toilet paper, especially at night or first thing in the morning | | A single worm that is much larger than a pinworm | Roundworm (Ascaris lumbricoides) | Uncommon in the US; usually linked to living in or traveling to places where it is common | | Short segments of a worm, sometimes moving | Tapeworm segments | The CDC says passing segments is the most visible sign of human tapeworm | | Nothing visible, but ongoing diarrhea or belly pain | Hookworm, whipworm or Strongyloides | These are usually found by a lab, not seen with the naked eye |

Pinworms

The CDC calls pinworm the most common worm infection in the United States. Female pinworms leave the intestine at night and lay eggs on the skin around the anus, which is why the main symptom is anal itching that is worse at night. Because the worms come out to lay eggs, people often see them on the skin, underwear or toilet paper rather than mixed into the stool. Our guide to pinworm treatment for adults covers how adults catch it and what to do at home. If you are wondering whether it needs treating at all, see what happens if pinworms go untreated.

Roundworms

The human roundworm is much larger than a pinworm. MedlinePlus lists passing worms in stool, and in some cases coughing up a worm or a worm leaving through the nose or mouth, among its possible symptoms. The CDC notes that people with a heavy infection may pass a worm in their stool or cough one up, and advises bringing the worm to a healthcare provider so it can be identified. See roundworm in humans for symptoms and how it spreads.

Tapeworm segments

Human tapeworms are caught by eating raw or undercooked beef or pork. MedlinePlus explains that people often realize they are infected when they pass segments of the worm in their stool, especially if the segments are moving, and the CDC lists this as the most visible sign. Tapeworm is a different kind of parasite. It is not covered by mebendazole's or ivermectin's labeling, and it needs a clinician's own assessment; see which parasites mebendazole's labeling covers.

Worms you usually can't see

Hookworm, whipworm and Strongyloides are rarely noticed in stool. They are usually found when a lab examines a stool sample under a microscope for eggs or larvae. If your symptoms are diarrhea, belly pain or tiredness rather than a visible worm, the hub page on intestinal worms in adults compares all five.

Could it be something other than worms?

Yes. Not everything that looks like a worm is one. Strands of mucus, plant fibers and other bits of food that were not fully digested can look thread-like in the toilet. That is one more reason to have a clinician or a lab confirm what you saw rather than treating on a guess.

Anal itching on its own also has many causes besides pinworm, such as hemorrhoids, skin conditions and irritation from soaps or wipes. See itchy anus at night: pinworms or not? for how to tell them apart.

What to do if you see worms in your stool

1. Don't panic. Pinworm, the most common worm infection in the US, usually causes mild symptoms, according to the CDC, and it is common in households with children.
2. Note what you saw: size, color, shape, whether it moved, and where (in the stool, on toilet paper, on underwear).
3. Keep a sample if you can. The CDC advises bringing a worm passed in stool to your healthcare provider. A clean, sealed container works; ask your clinician's office how they want it handled.
4. Wash your hands with soap and warm water, and wash underwear, pajamas and bedding in hot water if pinworm is possible.
5. Talk to a clinician about testing before choosing a medicine.

How worms in stool are diagnosed

The test depends on what a clinician suspects:

• Pinworm: a tape test. MedlinePlus describes pressing clear tape against the skin around the anus first thing in the morning, before bathing, so the eggs can be seen under a microscope. The CDC also lists looking for worms around the anus a few hours after the person falls asleep.
• Roundworm, hookworm, whipworm and tapeworm: a stool ova and parasite (O&P) test, in which a lab looks for eggs or worm parts. MedlinePlus notes that several samples over a few days may be needed. Our guide to the stool test for parasites explains how it works.
• A worm you brought in: a clinician or lab can often identify it directly.

How worms in stool are treated

Treatment depends on which worm it is, which is why identification comes first. Pinworm, roundworm, hookworm and whipworm are the four labeled uses in the prescribing information for the brand-name mebendazole chewable tablet. For pinworm only, an over-the-counter medicine, pyrantel pamoate, is sold in US pharmacies; see pinworm medicine: OTC or prescription?. Tapeworm needs a different medicine, chosen by a clinician.

The CDC advises treating everyone in a household with pinworm, and their caregivers, at the same time. The medicine, dose and timing are the prescriber's decision. We don't publish doses or schedules, so follow the directions on your own label. What is mebendazole gives background on the medicine.

When to see a clinician in person

Get prompt, in-person care if you:

• See blood in your stool, or have black, tarry stools
• Have severe or worsening belly pain, repeated vomiting or a swollen belly
• Vomit or cough up a worm
• Passed worm segments that could be tapeworm, especially after eating raw or undercooked pork
• Are pregnant or breastfeeding, have a weakened immune system, or the worm was found in a child

Getting a prescription online

If a clinician has confirmed pinworm, roundworm, hookworm or whipworm, or your history and test results clearly point to one of them, a licensed provider can review a written health assessment through Get It Prescribed and decide whether mebendazole is appropriate. There is a one-time $50 consultation fee, and mebendazole costs $3.50 per capsule, with the quantity decided by the prescriber. The service is available in all 50 states and the District of Columbia, and some states require a live phone or video visit. How it works shows each step. A prescription is never guaranteed, and the service is for adults only.

The mebendazole dispensed through Get It Prescribed is a compounded preparation made by a licensed compounding pharmacy for an individual patient. Compounded preparations are not FDA-approved, and the FDA does not review them for safety, effectiveness or quality. They are not generics of, or substitutes for, the brand-name product.

Related questions

What are the little white worms in my poop?

Small, thin, white worms about the size of a staple are most often pinworms, according to the CDC. They are usually seen around the anus, on underwear or on toilet paper, often at night. Strands of mucus or undigested food can look similar, so a clinician should confirm it, usually with a tape test.

Are white worms in stool serious?

Usually not. Pinworm is the most common worm infection in the US and its symptoms are usually mild. Get prompt care if you also have blood in your stool, severe belly pain or vomiting, if you vomit or cough up a worm, or if you passed worm segments that could be tapeworm.

What should I do if I see a worm in my stool?

Note what it looked like, keep it in a clean sealed container if you can, wash your hands well, and contact a clinician. The CDC advises bringing a worm passed in stool to your healthcare provider so it can be identified before treatment is chosen.

Can adults get worms in their stool?

Yes. Adults most often get pinworm from children in the home or from caring for someone who has it. Roundworm, hookworm and whipworm are uncommon in the US and are mostly linked to living in or traveling to places where sanitation is poor.

How do doctors test for worms in stool?

Pinworm is usually confirmed with a tape test pressed to the skin around the anus in the morning. Other worms are found with a stool ova and parasite test, which may need several samples. A clinician can also identify a worm you bring in.

Sources

• CDC: About Pinworm Infection — what pinworms look like, symptoms, how they spread, diagnosis and household treatment.
• CDC: About Ascariasis — the human roundworm, symptoms, and bringing a passed worm to a provider.
• CDC: About Human Tapeworm — how human tapeworm is caught and the passing of segments.
• MedlinePlus: Ascariasis — symptoms, including passing worms in stool, and diagnosis.
• MedlinePlus: Beef or pork tapeworm infection — symptoms and when to contact a provider.
• MedlinePlus: Pinworm test — how the tape test is done.
• MedlinePlus: Ova and Parasite Test — how the stool parasite test works and why several samples may be needed.
• DailyMed: mebendazole chewable tablet prescribing information — labeled uses: pinworm, whipworm, roundworm and hookworm.
• FDA: Compounding and the FDA — Questions and Answers — what compounded preparations are and how they are regulated.