E. Coli Symptoms
Digestive HealthE. Coli

E. Coli Symptoms and Types

E. Coli Symptoms and Types
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Updated on January 28, 2026
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Escherichia coli, commonly referred to as E. coli, is a type of bacteria that can cause foodborne intestinal infections such as food poisoning and traveler’s diarrhea. However, pathogenic E. coli can also cause a range of other symptoms outside of the digestive tract.

Here are the most common E. coli infections and their associated symptoms:

Symptoms

The symptoms you experience from an E. coli infection depend on what kind of infection occurs and where the infection is most concentrated.

However, most people with an E. coli intestinal infection experience bloody, runny diarrhea and sometimes severe stomach cramps.

 Watery diarrhea is often the first E. coli symptom.

Types

There are numerous types of E. coli bacteria that can cause food poisoning. While each brings about similar symptoms, there are slight variations.

Shiga Toxin–Producing E. Coli (STEC)

STEC is the type of E. coli infection most commonly seen on the news for the outbreaks it causes. An intestinal infection by STEC — which typically lives in cattle and migrates to humans when animal feces contaminate human food — results in:

  • Nausea
  • Severe stomach cramps
  • Diarrhea, which can be severe and bloody
  • Fatigue
  • Vomiting (rare)
  • Low-grade fever (rare)
While some people experience severe illness with a STEC infection, most people recover from STEC within about two weeks.

Enterotoxigenic E. Coli (ETEC)

This type of E. coli uses hairlike appendages to attach to the intestines, where it attacks the body with toxins.

 These bacteria are often the cause of traveler’s diarrhea.

 Fever can occur with this type of E. coli infection, though it is not common.

Enteroinvasive E. Coli (EIEC)

This type invades the cells lining the colon, leading to bloody diarrhea and sometimes fever. EIEC is generally rare, as acquiring it through eating food requires a large number of bacteria.

Enteropathogenic E. Coli (EPEC)

This form of E. coli attaches to intestinal cells using a special protein. EPEC causes watery and sometimes bloody diarrhea. It’s a common culprit in infantile diarrhea in developing countries.

Enteroaggregative E. Coli (EAEC)

EAEC builds up on the cells lining the intestines. Then, the toxin causes prolonged diarrhea, particularly in children, research has noted. According to recent research, EAEC is becoming more common as a cause of traveler’s diarrhea.

Medical illustration on How Intestinal E. Coli Infection Affects the Body, man centered surrounded by symptoms including nausea, fatigue, diarrhea, abdominal pain, vomiting (rarely), fever (rarely), Everyday Health logo located at bottom left hand corner
These are symptoms you may get from an infection with Shiga toxin–producing E. coli (STEC), the bacteria commonly linked to food poisoning outbreaks.Everyday Health

Complications

STEC is the most common cause of a complication called hemolytic uremic syndrome (HUS). This is a potentially life-threatening condition in which the red blood cells that the E. coli bacteria have destroyed damage the kidneys’ filtering system, which can lead to kidney failure.

Those who are most likely to develop HUS include children under 5 years of age and those with compromised or weakened immune systems or certain gene changes.

 People who take antibiotics to treat an E. coli infection may also have an increased risk of developing HUS, according to research.

Usually, HUS emerges about seven days after E. coli symptoms first appear — and once diarrhea starts to subside.

Symptoms may include:

  • Often bloody diarrhea
  • Abdominal pain, bloating, or cramps
  • Decreased urination or bloody urine
  • Vomiting
  • Fatigue
  • Fever, occasionally
  • Pale skin
  • Small, unexplained bruises or bruising more easily than usual
  • Confusion or seizures
  • Increased blood pressure
  • Swelling of the face, hands, feet, and body
  • Stroke

Seek immediate emergency care if the affected individual doesn’t urinate for 12 hours or more. Speak to a doctor if you or your child experiences bloody diarrhea or several days of nonbloody diarrhea followed by:

  • Decreased urine output
  • Unexplained bruising
  • Swelling
  • Unusual bleeding
  • Extreme fatigue

Urinary Tract Infections

E. coli bacteria are behind around 75 percent of all urinary tract infections (UTIs), according to research.

UTIs occur when E. coli, which typically lives in the colon, enters the urinary system through the urethra. This can happen through improper hygiene, like wiping from back to front after a bowel movement, or via sexual contact. A woman’s urethra is next to the vagina and anus, which creates an easy pathway for E. coli to enter the urinary tract.

With a urinary tract infection, you will likely experience at least one of the following signs:

Bacterial Meningitis

Meningitis is inflammation of the meninges, or the brain’s lining. E. coli is an uncommon but possible cause of bacterial meningitis. In the United States, bacterial meningitis was once more common. However, vaccinations have decreased its presence.

 Despite vaccines being available for other types, no E. coli meningitis vaccine is currently available, and it’s the third most significant bacterial meningitis cause in infants under a month of age. In 2021, E. coli led to about 1,500 deaths in this age group, according to the Meningitis Research Foundation.

Babies born preterm and those born at a low birth weight have an increased risk of contracting this type of meningitis. An E. coli strain called K1 accounts for the vast majority of E. coli–related neonatal meningitis cases.

Newborns may acquire E. coli K1 during birth or later on in the hospital or at home. That said, all types of bacterial meningitis are very rare in developed countries. E. coli meningitis is far rarer in older children and adults, but the risk may be higher in individuals with compromised immune systems, head injuries, or a device for draining brain fluid to relieve pressure called a cerebrospinal fluid shunt (CSF shunt).

A newborn with meningitis may experience one or more of the following symptoms:

  • Fever, but body temperature can also be normal or low
  • Irritability
  • Refusing to feed
  • Vomiting
  • High-pitched crying
  • A stiff body that makes jerky movements
  • A bulging or tense soft area on top of the infant’s head
  • Extreme sleepiness or a baby being difficult to wake
  • A staring expression

In other populations, symptoms might include:

  • Fever
  • Vomiting
  • A painful headache
  • Extreme lethargy and finding waking challenging
  • Seizures
  • Discomfort when looking at bright lights
  • Neck stiffness, most often in adults

Sepsis

E. coli can also put newborns and babies at risk of septicemia, or blood poisoning. Infection of the blood is a common cause of neonatal sepsis, which occurs in babies less than 90 days old. The infection can transmit to babies from the mother before, during, or after delivery.

Signs and symptoms include:

Neonatal sepsis is a serious health problem and a leading cause of infant death. The more quickly an infant gets diagnosed and treated with antibiotics, the better the outcome.

Pneumonia

Streptococcus pneumoniae is the most common bacterial cause of pneumonia. However, E. coli can also occasionally cause the disease, according to the Centers for Disease Control and Prevention.

 The most common bacterial pneumonia symptoms include:

  • Chest pain when breathing or coughing
  • Cough with phlegm, which might contain blood
  • Breathlessness
  • Nausea, vomiting, or diarrhea
  • Fatigue
  • A high fever, up to 105 degrees F
  • An unusually fast heartbeat
  • Chills
  • Sweating
  • Confusion or changes in mental awareness
  • Abdominal pain
  • Cyanosis, which refers to blue-tinted skin, nails, or lips

The Takeaway

  • E. coli symptoms commonly include diarrhea and stomach cramps, but symptoms may vary depending on the type of E. coli causing the infection.
  • Those experiencing symptoms such as bloody diarrhea, severe stomach cramps, or reduced urination should consult with a healthcare provider promptly for appropriate testing and treatment, to avoid dangerous outcomes.
  • In children, older adults, and those with weakened immune systems, E. coli can lead to more severe problems, including sepsis or neonatal meningitis, which warrant urgent medical attention.
  • Although dietary precautions and hygiene can prevent the spread of E. coli, always consult healthcare professionals for management, as the evidence on effective supplement interventions remains limited.

FAQ

What are the symptoms of enterotoxigenic E. coli infection?

Symptoms of this type of intestinal E. coli infection include diarrhea. Fever may occur but is less common.

This type of E. coli infection causes diarrhea with fever.
Enteroaggregative E. coli infection, which affects the cells lining the intestines, causes prolonged diarrhea, particularly in children.
Symptoms of urinary tract infections due to E. coli include a burning feeling during urination, and frequent urination.
Symptoms of E. coli meningitis in a newborn may include respiratory irritability, seizures, vomiting, jaundice, extreme sleepiness, staring, and a bulging soft spot on the skull.

Resources We Trust

EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. About Escherichia coli Infection. Centers for Disease Control and Prevention. May 14, 2024.
  2. E. coli Infection. Cleveland Clinic. November 22, 2023.
  3. Kinds of E. coli. Centers for Disease Control and Prevention. May 14, 2024.
  4. Escherichia coli Infection. StatPearls . July 13, 2023.
  5. E. coli Infection. Cleveland Clinic. November 22, 2023.
  6. Hemolytic Uremic Syndrome (HUS). Mayo Clinic. September 12, 2025.
  7. Mody RK et al. Risk of Hemolytic Uremic Syndrome Related to Treatment of Escherichia coli O157 Infection With Different Antimicrobial Classes. Microorganisms. September 20, 2021.
  8. Management and Investigation of Bloody Diarrhoea and Haemolytic Uraemic Syndrome. National Health Service.
  9. Zhou Y et al. Urinary Tract Infections Caused by Uropathogenic Escherichia coli: Mechanisms of Infection and Treatment Options. International Journal of Molecular Sciences. June 23, 2023.
  10. Urinary Tract Infection (UTI). Mayo Clinic. September 26, 2025.
  11. Runde TJ et al. Bacterial Meningitis. StatPearls. August 8, 2023.
  12. E. coli meningitis. Meningitis Research Foundation. March 31, 2025.
  13. Neonatal Sepsis. MedlinePlus. April 25, 2023.
  14. Pneumonia. Cleveland Clinic. November 15, 2022.
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Jane Yoon Scott, MD

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Jane Yoon Scott, MD, is an infectious disease physician and an assistant professor of medicine at Emory University in Atlanta. Dr. Scott enjoys connecting with her patients, empowering them to understand and take ownership of their health, and encouraging them to ask questions so that they can make informed and thoughtful decisions.

She graduated with the highest honors from the Georgia Institute of Technology, then received her MD from the Medical College of Georgia. She completed her internal medicine residency training and chief residency at Temple University Hospital, as well as a fellowship in infectious diseases at Emory University. She is board-certified in both internal medicine and infectious diseases.

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