Published July 21, 2026 | Last updated July 21, 2026

Parasitic diarrhea is receiving national attention as the Centers for Disease Control and Prevention investigates a multistate outbreak of Cyclospora infections associated with recalled iceberg lettuce.

Cyclospora cayetanensis is a microscopic parasite that infects the small intestine and causes an illness called cyclosporiasis. Its primary symptom is frequent watery diarrhea, which may last for weeks, temporarily improve and then return.

As of July 18, 2026, the CDC reported more than 1,644 illnesses and 94 hospitalizations connected to the identified five-state outbreak. No deaths had been reported. The investigation remains open, and additional Cyclospora illnesses being investigated nationally may be unrelated to this outbreak.

Below, we answer the most common questions about parasitic diarrhea, including what Cyclospora symptoms feel like, how the infection spreads, how testing works, which treatment is used and when to contact a healthcare provider.

Current Cyclospora outbreak at a glance

Information last verified: July 20, 2026
CDC investigation status: Open
Illnesses linked to the identified outbreak: More than 1,644
Hospitalizations: 94
States involved in the identified outbreak: Five
Food involved: Recalled iceberg lettuce sourced by Taylor Farms de Mexico from central Mexico

Taylor Farms initiated a recall on July 17, 2026, involving iceberg lettuce sold through retailers, restaurants and food-service businesses. The CDC advises consumers not to eat recalled iceberg lettuce and to discard it or return it to the place of purchase.

Outbreak totals, affected products and recall guidance may change as the investigation continues.

Frequently Asked Questions About Parasitic Diarrhea

What parasite is causing the recent diarrhea outbreak?

The current outbreak receiving national attention involves Cyclospora cayetanensis, a microscopic parasite that causes an intestinal illness called cyclosporiasis.

As of July 18, 2026, the identified five-state outbreak included more than 1,644 illnesses and was associated with recalled iceberg lettuce.

Is explosive diarrhea a symptom of Cyclospora?

Cyclospora commonly causes frequent watery diarrhea, which may sometimes be sudden or explosive. That symptom alone cannot diagnose the infection.

Can Cyclospora go away without treatment?

Most people with healthy immune systems eventually recover without treatment. However, symptoms may continue for more than a month and can disappear and then return. Contact a healthcare provider to determine whether prescription treatment is appropriate.

How do doctors test for a parasite causing diarrhea?

Doctors generally use stool testing. Because a standard stool test may not include every parasite, ask whether the ordered panel specifically tests for Cyclospora.

Can a stool test miss Cyclospora?

Yes. Cyclospora can be difficult to detect, and patients may need to provide several stool samples collected on different days. Specialized testing must be specifically requested.

Can you see Cyclospora in your stool?

No. Cyclospora is microscopic and cannot typically be identified by looking at the stool.

Can Cyclospora spread through a household?

Direct person-to-person transmission is unlikely because Cyclospora generally needs at least one to two weeks outside the body to become infectious. Handwashing and bathroom hygiene remain important.

Can you get Cyclospora more than once?

Yes. A previous Cyclospora infection does not provide guaranteed lifelong immunity, and people can become infected more than once.

Can you get Cyclospora from lettuce?

Yes. Leafy greens and other fresh produce can become contaminated with Cyclospora. The current identified outbreak has been linked to recalled iceberg lettuce sourced by Taylor Farms de Mexico from central Mexico.

Is it safe to eat lettuce during the outbreak?

No. The outbreak and recall do not mean that all lettuce is contaminated. Avoid products identified by official recall notices and follow current CDC and FDA guidance.

Will washing bagged salad remove Cyclospora?

Washing can reduce some surface contamination, but it cannot guarantee removal of Cyclospora. Do not eat a recalled product, even after washing it.

What temperature kills Cyclospora?

The CDC advises cooking produce to at least 158°F, or 70°C, to kill Cyclospora.

What medicine is used for Cyclospora?

The standard prescription treatment is trimethoprim-sulfamethoxazole, or TMP-SMX. A healthcare provider must determine whether this medication is appropriate for you.

Do probiotics kill Cyclospora?

No. Probiotics do not eliminate Cyclospora and should not replace diagnostic testing or prescription care. It is important to strengthen your gut prior. 

What should you eat while recovering from parasitic diarrhea?

Prioritize hydration and eat simple foods you tolerate. Gradually return to balanced meals as symptoms improve and follow individualized medical guidance.

How long should diarrhea last before you see a doctor?

Contact a healthcare provider when watery diarrhea lasts more than a few days, repeatedly returns or is accompanied by dehydration, weight loss, severe weakness, blood, fever or intense abdominal pain.

What should you do during the Cyclospora outbreak?

Do not eat recalled iceberg lettuce. Throw it away or return it to the store where it was purchased.

Wash containers, refrigerator drawers, knives, cutting boards, countertops and other items that may have touched the recalled lettuce using hot, soapy water or a dishwasher. If you are eating at a restaurant and do not know the source of its iceberg lettuce, ask before ordering it.

Contact a healthcare provider if you develop watery diarrhea, fatigue or loss of appetite after a possible exposure. Routine stool testing does not always screen for Cyclospora, so ask whether the test being ordered specifically includes the parasite.

Stay hydrated, particularly when diarrhea is frequent. Seek urgent medical care for severe dehydration, fainting, confusion, very little urination, blood in the stool or an inability to keep fluids down.

What is the quick answer?

Cyclospora is a foodborne parasite that can cause prolonged watery diarrhea, abdominal cramping, bloating, appetite loss, fatigue and weight loss. Symptoms usually begin about one week after exposure. Diagnosis requires stool testing that specifically detects Cyclospora, and the standard prescription treatment is trimethoprim-sulfamethoxazole, or TMP-SMX.

Probiotics, digestive enzymes, chlorophyll and over-the-counter parasite cleanses do not eliminate Cyclospora and should not replace diagnostic testing or medical care.

What is parasitic diarrhea?

Parasitic diarrhea is diarrhea caused by a parasite that infects the gastrointestinal system.

Intestinal parasites can enter the body through contaminated food, water, soil or contact with infected material. Examples of parasites that may cause diarrhea include:

• - Cyclospora

• - Giardia

• - Cryptosporidium

• - Entamoeba histolytica

The current U.S. outbreak receiving widespread attention involves Cyclospora cayetanensis.

Symptoms alone cannot determine which parasite or other organism is causing diarrhea. Viruses, bacteria, medications, food intolerances and inflammatory digestive conditions may produce similar symptoms.

What is Cyclospora?

Cyclospora cayetanensis is a microscopic, single-celled parasite that infects the small intestine.

The illness caused by the parasite is called cyclosporiasis. People usually become infected by consuming food or water contaminated with Cyclospora.

In the United States, Cyclospora outbreaks have previously been associated with several kinds of fresh produce. The illness is generally not life-threatening, but it can be prolonged and particularly difficult for people who are already in poor health or immunocompromised.

What are the symptoms of Cyclospora?

The primary symptom of Cyclospora infection is frequent, watery diarrhea.

Bowel movements may sometimes be sudden or explosive. Symptoms can improve for a short period and then return.

Other common Cyclospora symptoms include:

• - Abdominal cramping

• - Bloating

• - Increased gas

• - Nausea

• - Loss of appetite

• - Unintentional weight loss

• - Fatigue

Some people may also experience vomiting, headache, body aches or a low-grade fever.

Not everyone who becomes infected develops symptoms. People who are immunocompromised or in poor health may be more likely to experience a severe or prolonged illness.

How soon do Cyclospora symptoms begin?

Cyclospora symptoms usually begin about one week after consuming contaminated food or water.

The incubation period may range from approximately two days to two weeks or longer. This delay can make it difficult to identify the meal or food responsible for the infection.

When speaking with a healthcare provider or public-health official, consider foods eaten during the previous two weeks, not only what you ate immediately before symptoms began.

How long does parasitic diarrhea from Cyclospora last?

Without treatment, Cyclospora symptoms may last from several days to more than a month.

A notable feature of cyclosporiasis is its relapsing pattern. Diarrhea and other symptoms may appear to resolve and then return one or more times. Fatigue and digestive sensitivity may also continue after the most severe diarrhea improves.

A healthcare provider can determine whether prescription treatment is appropriate.

What does Cyclospora diarrhea look like?

Cyclospora most commonly causes frequent, loose or watery stool.

The appearance of stool cannot confirm the infection. Watery diarrhea can also result from viruses, bacteria, medications, food intolerances and other gastrointestinal conditions.

Cyclospora is microscopic. It is not typically visible in the stool as a worm or other recognizable organism.

Is Cyclospora contagious?

Cyclospora is not usually transmitted directly from one person to another.

After Cyclospora leaves an infected person’s body through a bowel movement, it generally must remain in the environment for at least one to two weeks before becoming infectious.

This makes immediate person-to-person transmission unlikely. People more commonly become infected through food or water contaminated with fecal matter containing mature Cyclospora.

Thorough handwashing is still important, especially after using the bathroom and before preparing food.

What foods can carry Cyclospora?

Cyclospora outbreaks have historically been associated with fresh produce, particularly foods that are commonly eaten raw.

Foods associated with past outbreaks have included:

• - Leafy greens

• - Packaged salad mixtures

• - Fresh herbs

• - Berries

• - Raw vegetables

Produce can become contaminated through water, agricultural environments, processing equipment or handling.

An outbreak involving one product does not mean that all produce is unsafe. Follow current CDC and FDA recall notices rather than avoiding entire food categories indefinitely.

Can washing lettuce remove Cyclospora?

Washing fruits and vegetables under clean running water can reduce dirt and some surface contamination, but it cannot guarantee that Cyclospora has been removed.

The parasite may remain within the folds, crevices and uneven surfaces of leafy vegetables.

Do not wash produce with:

• - Dish soap

• - Hand soap

• - Bleach

• - Household disinfectants

• - Cleaning sprays

These products are not designed for consumption.

If lettuce or another product has been recalled, do not attempt to make it safe by washing it. Discard it or return it according to the recall instructions.

Does cooking kill Cyclospora?

The CDC advises that cooking produce to at least 158°F, or 70°C, can kill Cyclospora. Washing alone cannot guarantee the parasite has been removed.

This is one reason outbreaks are more commonly associated with raw produce than with properly cooked foods.

People who are particularly vulnerable to dehydration or prolonged illness may feel more comfortable choosing cooked produce while an active outbreak is being investigated.

How is Cyclospora diagnosed?

Cyclospora is diagnosed through stool testing, but the infection may be missed unless the appropriate test is ordered.

Not every routine stool panel includes Cyclospora. The parasite may also be difficult to detect even when symptoms are present.

A healthcare provider may request:

• A gastrointestinal PCR panel that includes Cyclospora

• A stool ova-and-parasite examination with Cyclospora-specific testing

• Several stool samples collected on different days

The CDC notes that identification of Cyclospora requires specialized laboratory testing that is not part of routine stool testing.

A useful question to ask your healthcare provider is:

Does this stool test specifically include Cyclospora cayetanensis?

Tell your provider about recalled-food exposure, recent travel, raw produce consumption and any other people who became ill after eating the same food.

Can a stool test miss Cyclospora?

Yes. A stool test can miss Cyclospora if the panel does not specifically include the parasite or if Cyclospora is not present in the particular sample collected.

Patients may need to submit several stool samples on different days. A single negative test does not always exclude cyclosporiasis when symptoms and exposure history strongly suggest it.

Do not assume that a general “parasite test” automatically includes Cyclospora.

When should you be tested for Cyclospora?

Contact a healthcare provider if you experience prolonged or recurring watery diarrhea, particularly when:

• - Diarrhea continues for more than a few days

• - Symptoms improve and then return

• - You recently ate a recalled food

• - You consumed raw leafy greens during an outbreak

• - You are losing weight

• - You feel unusually weak or fatigued

•  - You are having difficulty remaining hydrated

• - You are pregnant or immunocompromised

• - The person affected is a young child or older adult

Testing matters because Cyclospora requires a different treatment approach than many common stomach infections.

How is Cyclospora treated?

The standard treatment for cyclosporiasis is the prescription medication trimethoprim-sulfamethoxazole, commonly known as TMP-SMX and sold under brand names including Bactrim and Septra.

The appropriate medication, dosage and duration must be determined by a healthcare professional.

People with a serious sulfa allergy should tell their provider before beginning treatment. There is no consistently effective alternative medication for every person who cannot take TMP-SMX, so individualized medical guidance is important.

People who are immunocompromised or in poor health may experience a more severe or prolonged illness and should receive individualized care.

Does metronidazole treat Cyclospora?

Metronidazole, sometimes known by the brand name Flagyl, is used for certain intestinal infections, but it is not the standard treatment for Cyclospora.

Medications used for one parasite may not work against another. Properly identifying the organism is important because parasitic infections are not interchangeable and do not all respond to the same treatment.

Do not take leftover antibiotics or antiparasitic medication without medical guidance.

Do parasite cleanses treat Cyclospora?

No over-the-counter parasite cleanse or dietary supplement has been proven to eliminate Cyclospora.

Herbal cleanses, chlorophyll, probiotics and digestive enzymes should not be used as alternatives to stool testing or prescription treatment.

Some cleanse products contain laxative ingredients that may worsen diarrhea, dehydration and electrolyte loss.

Avoid trying to “flush out” the parasite. Contact a healthcare professional for persistent watery diarrhea and ask whether Cyclospora-specific testing is appropriate.

Can probiotics or digestive enzymes treat parasitic diarrhea?

Probiotics and digestive enzymes do not kill Cyclospora and do not treat an active parasitic infection.

During active diarrhea, the priorities are:

1. Replacing lost fluids

2. Obtaining medical evaluation when needed

3. Completing appropriate stool testing

4. Taking prescribed treatment as directed

5. Eating foods that are tolerated

It may be appropriate to pause nonessential supplements if they increase nausea, cramping or diarrhea. Ask a healthcare provider before beginning or continuing supplements during an active gastrointestinal illness.

How can you prevent dehydration from diarrhea?

Frequent watery diarrhea can cause the body to lose water and electrolytes.

Take small, frequent sips of fluid rather than drinking a large amount at once. When diarrhea causes significant fluid loss, ask a healthcare provider or pharmacist whether an oral rehydration solution is appropriate.

Foods that may be easier to tolerate temporarily include:

• - Bananas

• - Rice

• - Oatmeal

• - Potatoes

• - Toast

• - Applesauce

• - Broth

• - Plain crackers

• - Simple soups

Avoid alcohol while dehydrated. Large amounts of caffeine, spicy foods, high-fat meals and very fibrous foods may worsen symptoms for some people.

When is parasitic diarrhea an emergency?

Seek immediate medical care for:

• - Fainting or confusion

• - Inability to keep fluids down

• - Very little or no urination

• - A rapid heartbeat

• - Severe weakness

• - Severe or worsening abdominal pain

• - Blood in the stool

• - Black or tar-like stool

• - High fever

• - Significant symptoms during pregnancy

• - Signs of dehydration in a child or older adult

Blood in the stool and high fever are not the most characteristic Cyclospora symptoms and may indicate a different infection or medical condition.

 

After the infection: returning to your normal digestive routine

An intestinal infection can leave the digestive system feeling temporarily sensitive. Appetite, bowel habits and tolerance for certain foods may take time to return to normal.

Once the infection has been appropriately evaluated and symptoms have fully resolved, you can gradually return to your usual wellness routine based on your healthcare provider’s guidance.

Helpful steps may include:

• Reintroducing food gradually

• Continuing to prioritize hydration

• Returning to balanced meals as tolerated

• Paying attention to temporary changes in dairy or fiber tolerance

• Avoiding unnecessary restrictive diets

• Discussing persistent symptoms with a healthcare provider

Juna’s 3-in-1 Digestive Enzymes combine 15 digestive enzymes, five probiotics and eight herbs to support food breakdown and everyday digestive comfort.

They are formulated for everyday digestive support. They do not treat Cyclospora, parasitic diarrhea or another gastrointestinal infection.

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The bottom line

Cyclospora is more than an ordinary stomach bug. It can cause prolonged watery diarrhea, abdominal discomfort, appetite loss, fatigue and weight loss, with symptoms that may improve and then return.

Because Cyclospora is not included in every routine stool test, asking specifically about Cyclospora testing can be an important step.

During the current outbreak:

• Do not eat recalled iceberg lettuce

• Clean surfaces that may have touched recalled lettuce

• Ask whether your stool test specifically includes Cyclospora

• Stay hydrated during diarrhea

• Seek care for prolonged, recurring or severe symptoms

• Do not use supplements or parasite cleanses in place of established treatment

Follow the latest CDC and FDA recall guidance, and contact a qualified healthcare professional for personal medical advice.

About the author

Written by Taylor Lamb, Co-Founder of Juna

Taylor completed Cornell University’s Medicinal Plants certificate program and writes about plant-powered wellness, digestive health and evidence-informed daily rituals.

Article updates

July 20, 2026: Published with current CDC outbreak totals, recall guidance, symptom information, testing guidance, treatment information and food-safety recommendations.

This article will be updated when the CDC or FDA announces a meaningful change to the outbreak count, investigation status, recalled products or public-health guidance.

Sources

• Centers for Disease Control and Prevention. “Cyclospora Outbreak Linked to Iceberg Lettuce in 5 States.” Updated July 18, 2026.

• Centers for Disease Control and Prevention. “About Cyclosporiasis.” Updated July 14, 2026.

• Centers for Disease Control and Prevention. “Clinical Care of Cyclosporiasis.”

Medical disclaimer

This article is provided for educational purposes only and is not medical advice. Juna products are not intended to diagnose, treat, cure or prevent disease. Contact a qualified healthcare professional for individualized guidance.