If you have intestinal parasites, you may have digestive symptoms, including abdominal pain and diarrhea. Untreated worms may cause complications.

Intestinal parasites, including intestinal worms, affect over one billion people worldwide. They are more commonly found in subtropical and tropical regions, but some are in the United States.

Most intestinal worm infections cause mild illness and can be treated with medication. Read on to learn more about intestinal worms, including signs, symptoms, and treatment.

Here’s an example of what intestinal worms look like:

Common flatworm infections are:

Common roundworm infections are:

In the United States, pinworms are the most common type of intestinal worm infection, especially among children.

Depending on the type, intestinal worms can be acquired in various ways. One way to contract intestinal worms is by eating undercooked meat from an infected animal, such as a cow, pig, or fish.

Other possible causes leading to intestinal worm infection include:

However, intestinal worms can also be contracted while living in a climate where they are more common, such as a tropical climate.

You can also get worms from exposure to people who have already contracted them or surfaces these people have touched. That’s why pinworms are more common in young children, who may still be working on good hand hygiene and often play in environments with contaminated soil, such as sandboxes and school playgrounds. Older adults with weakened immune systems are also at increased risk.

According to the World Health Organization (WHO), an estimated 24% of the world’s population contracts soil-transmitted worms. Infections are most common in tropical and subtropical regions.

People living in and visiting developing countries are at the highest risk due to drinking water from sources containing the parasite and decreased sanitation levels.

Worms in your gut eventually pass through your digestive system and are excreted in your feces. Even if you don’t have any symptoms, you may find signs of worms in your stool.

Worms in human poop can take several appearances. For roundworms, you may find pieces of worms or large, live worms in your feces.

For pinworms, you may see thin, white worms that appear like pieces of thread. Pinworms, which are about the length of a staple, are sometimes visible around the anal region at night when females lay their eggs on the surrounding skin.

A doctor can analyze a sample of your stool in a lab for signs of worms or eggs that can confirm a diagnosis.

Once you contract it, the parasite travels into your intestines. There, it reproduces and grows. Once it reproduces and becomes larger in amount and size, symptoms may appear.

A person with intestinal worms may also experience dysentery. Dysentery occurs when an intestinal infection causes diarrhea with blood and mucus in the stool. Intestinal worms can also cause a rash or itching around the rectum or vulva. Sometimes, a worm is passed in the stool during a bowel movement.

Some people may have intestinal worms for years without experiencing any symptoms.

Intestinal worms increase the chance of developing anemia, intestinal blockages, and malnutrition.

These complications occur more frequently in older adults and in people with suppressed immune systems, such as people living with human immunodeficiency virus (HIV).

Intestinal worm infections can also pose a higher risk to pregnant people. If you’re found to have an intestinal worm infection, your doctor will determine which antiparasitic medication therapy is safe to take during pregnancy and will monitor you closely while you are treated.

Most types of worms that infect humans only cause mild symptoms, but it’s still important to contact a doctor if you suspect a worm infection so you can get treated early. Medication is often effective at getting rid of worms.

It’s a good idea to see your doctor if you:

  • have blood or pus in your stool
  • are vomiting daily or frequently
  • have an elevated body temperature
  • are extremely fatigued and dehydrated
  • are losing weight for no obvious reason
  • feel sick, have diarrhea, or have stomach pain for more than 2 weeks
  • have a red and itching rash on your skin shaped like a worm

If you have any of the above signs, especially if you have recently traveled out of the country, you should make an appointment with a doctor. The doctor may then examine your stool. It may take several stool samples to confirm the parasite’s presence.

Another test is the “Scotch tape” test, which involves applying tape to the anus several times to retrieve pinworm eggs, which can be identified under a microscope.

If worms or eggs are not detected, a doctor may perform a blood test to look for antibodies the body produces after it contracts a parasite. However, only some parasites are detectable with blood tests.

Additionally, depending on the extent or location of the condition suspected, a doctor may take an X-ray or use imaging tests such as computed tomography (CT) or magnetic resonance imaging (MRI).

Some types of intestinal worms, such as tapeworms, may disappear independently if you have a strong immune system and a healthy diet and lifestyle. However, depending on the type of intestinal worm infection, you may require treatment with an antiparasitic medication.

Your treatment plan will be determined based on the type of intestinal worm you have and your symptoms.

Tapeworm infections are usually treated with an oral medication, such as praziquantel (Biltricide), which:

  • paralyzes adult tapeworms
  • causes the tapeworms to detach from the gut
  • dissolve
  • pass out of your body through your stool

Common treatments for a roundworm infection include mebendazole (Vermox, Emverm) and albendazole (Albenza).

Medications for intestinal worms are usually taken for 1 to 3 days. Symptoms typically begin to improve within a few weeks. Your doctor will most likely take and analyze another stool sample after treatment is complete to see if the worms have disappeared.

How can you deworm yourself?

If you look on the Internet, you’ll find various ideas for natural parasite cleanses. However, there is not enough research evidence to support them.

If you think you have an intestinal worm, it’s first and foremost important to know which kind. Usually, the only way to tell is to see your doctor. They can then make sure you get the right treatment.

To prevent intestinal worms, regularly wash your hands with soap and hot water before and after using the toilet and before preparing or eating food.

You should also practice food safety:

  • avoid raw fish and meat
  • thoroughly cook meat to temperatures of at least 145°F (62.8°C) for whole cuts of meat and 160°F (71°C) for ground meat and poultry
  • let cooked meat rest for 3 minutes before carving or consuming
  • wash, peel, or cook all raw fruits and vegetables
  • wash or reheat any food that falls on the floor

If you’re visiting developing countries, cook fruits and vegetables with boiled or purified water before eating, and avoid contact with soil that may contain human feces.

Factors that make it more likely to get worms include eating not fully cooked meat or seafood, sharing your personal stuff with others, or drinking or swimming in unclean water.

Some worm infections might not show symptoms or only have mild discomfort, but others could become really bad if they’re not treated quickly.

If you think you might have worms in your belly, it’s important to see a doctor immediately so they can figure out what’s going on and treat you with the right medication.