Symptoms of E. Coli

A gastrointestinal (GI) infection with Escherichia coli (E. coli) causes symptoms that include nausea, vomiting, and diarrhea. Complications of some strains can include dehydration and kidney failure.

A GI infection with E. coli can cause major disruptions to the stomach and intestines. Sometimes these disruptions are fatal if a person doesn’t get treatment for complications if they arise. Pregnant people, older adults, and children are at a higher risk of complications.

This article will describe frequent and rare symptoms of E. coli GI infection and review the complications of this infection. It will review when you should see a healthcare provider about your E. coli symptoms. 

Types of E. Coli

E. coli bacteria are typically found in the intestines and are usually harmless. But, multiple kinds of E. coli (pathogenic E. coli) can cause symptoms and complications. You may be exposed to these bacteria through water, food, live animals, or from other people.

The pathogenic E. coli that infect the gastrointestinal tract and cause diarrhea are divided into six types. They can cause slightly different symptoms and complications, though they all cause intestinal distress:

• Shiga toxin-producing E. coli (STEC), which may also be called enterohemorrhagic E. coli (EHEC) or verocytotoxic E. coli (VTEC). These E. coli strains produce toxins that damage the intestines and cause bleeding. STEC is the type most often discussed in the news and leads to outbreaks in the United States, sometimes called E. coli 0157.
• Enterotoxigenic E. coli (ETEC) is also known as travelers' diarrhea, often causing diarrhea in children in lower-income countries.
• Enteropathogenic E. coli (EPEC) causes diarrhea but does not produce Shiga or enterotoxins.
• Enteroaggregative E. coli (EAEC) leads to watery diarrhea with mucus, abdominal pain, vomiting, and low fever. It usually improves on its own, but some people may have it for two weeks or more.
• Enteroinvasive E. coli (EIEC) can cause dysentery and bloody diarrhea without the more dangerous complications of EHECs. It's less common in the United States.
  
• Diffusely adherence E. coli (DAEC) is a less well-defined type of E. coli infection.

Frequent Symptoms

Gastrointestinal (digestive system) symptoms of E. coli are typically mild but can be severe in the most susceptible people and with certain strains. Most E. coli GI infection cases get better without treatment in five to 10 days.

When you get E. coli, your body tries to eliminate the bacteria. That typically causes symptoms that affect the stomach and intestines. E. coli can sit in your body for three or four days before causing illness. 

Symptoms of gastrointestinal infection with E. coli include:

• Nausea 
• Vomiting
• Severe abdominal cramps
• Watery diarrhea
• Fatigue
• Fever

The disease first starts as severe, sudden stomach cramps. Watery diarrhea starts a few hours later and lasts for about a day. You might have to go to the bathroom more than 10 times daily.

The best way to recover for most is to drink plenty of fluids and get rest. Then, when your stomach starts feeling better, slowly try eating some basic carbohydrates, like crackers. Avoid high-fiber foods. Most people feel better six to eight days later.

Rare Symptoms

Excessive diarrhea and an inability to hold down food or water can lead to dehydration, where the body doesn’t have enough water. Dehydration symptoms include:

• Fatigue 
• Muscle weakness or pain
• Headache
• Dizziness or lightheadedness
• Urinating less or having dark urine (with a strong odor)
• Increased heart rate and breathing

STEC may cause bloody diarrhea. Sores develop in the intestines and start bleeding, which for many turns the diarrhea bright red for two to five days. This symptom is not part of benign self-limited E.coli infection and should be discussed with a healthcare provider.

STEC infections, which produce Shiga toxin, can lead to more severe symptoms and complications and can be deadly.

Five to 10% of people with STEC infections develop hemolytic uremic syndrome (HUS). HUS develops when the bacteria make toxins that lower your red blood cell count, a symptom called anemia. The toxins also decrease your platelet count, called thrombocytopenia.

Broken-up bits of red blood cells and platelets start to clog the kidneys, reducing their ability to function. HUS usually affects young children and older adults, but can occur at any age.

HUS may develop about one week after symptoms of E. coli begin when your diarrhea starts to subside. It’s a sign that your kidneys are having trouble making urine.

Symptoms of HUS include:

• Decreased urine production
• Irritability
• Dark, tea-colored, or bloody urine
• Pale cheeks
• Restlessness, sleepiness, and seizures
• Little purple bruises on the skin
• Increased blood pressure
• Fatigue
• Swelling
  

HUS is a precursor to kidney failure; someone who develops it must go to the hospital. People with HUS lose kidney function and develop other serious problems. Most people with HUS recover within a few weeks, but some experience permanent damage or die.

Complications

People most at risk of complications from E. coli include children and adults with weak immune systems. These people are more likely to develop a severe illness due to an E. coli infection. However, even healthy older children and young adults can become seriously ill.

People at risk of complications of E. coli include:

• Children under 5
• Adults older than 65
• People with weakened immune systems

STEC infections that lead to HUS can cause chronic kidney disease and kidney failure (your kidneys stop working right). Kidneys remove waste products and toxins from your blood and release them in urine. Symptoms of kidney failure include:

• Swelling of the legs, ankles, or feet
• Nausea
• Shortness of breath
• Chest pain or pressure
• Confusion

Additional long-term complications of E. coli infection include:

• High blood pressure
• Heart disease 
• Neurologic problems

Kids with untreated EAEC infections in low-income countries may develop chronic inflammation in their guts. This can reduce the intestine’s ability to absorb nutrients, causing malnutrition and persistent diarrhea. Malnutrition can lead to stunted physical and intellectual growth.

These complications can be deadly if a person can’t get medical care. These diarrheal illnesses can hurt and kill infants and young children if they can’t get medical care when complications arise.

In rare circumstances, E.coli that infects the GI tract may infect other organs and spread to the bloodstream, causing bacteremia. Most often, bacteremia caused by E. coli comes from infection with other strains of E. coli in another part of the body, including the urinary tract, the bile duct, or other abdominal organs.

When to See a Healthcare Provider

If you suspect you have an E. coli infection, you should see a healthcare provider if you:

• Are immunocompromised (have a weakened immune system) or very young or very old
• Cannot drink enough fluids to prevent dehydration 
• Have severe symptoms (bloody diarrhea or severe stomach pain)
• Have diarrhea for more than three days 
• Also have a fever higher than 102 F
• Are passing very little urine 

Summary 

Escherichia coli can cause gastrointestinal infection. Symptoms include nausea, vomiting, severe abdominal cramps, watery or bloody diarrhea, fever, and exhaustion. 

Symptoms and complications of E. coli can be fatal if a person doesn’t get treatment. Pregnant people, older adults, and children are at a higher risk of complications. Most cases of E. coli infection get better without treatment in five to 10 days. Complications can include dehydration, kidney damage, and a lowered red blood cell or platelet count. 

Some people with toxin-producing E. coli infections develop hemolytic uremic syndrome about one week after symptoms of E. coli begin. It’s a sign that the kidneys are having trouble making urine. It can lead to chronic kidney disease and kidney failure.

In the long term, people with E. coli GI infections may develop high blood pressure, heart disease, and neurologic problems. Kids with certain types of E. coli infections can develop chronic inflammation in their guts. This can reduce the intestine’s ability to absorb nutrients, causing malnutrition. Malnutrition can lead to stunted physical and intellectual growth.