E. coli is a type of bacteria that normally lives in your intestines and is usually harmless. However, some strains of E. coli can cause infection and lead to diarrhea and other intestinal problems. E. coli is spread through contaminated food or water, or contact with feces. Once E. coli enters your body, it travels through your digestive system and ultimately exits your body through feces. Read on to learn more about the journey E. coli takes through your body and how it exits in stool.
How E. coli enters your body
E. coli enters your body through your mouth, usually by eating contaminated food or drinking contaminated water. Foods commonly associated with E. coli outbreaks include:
- Undercooked ground beef or other beef products
- Raw milk or unpasteurized dairy products
- Contaminated raw fruits and vegetables like spinach, lettuce, and sprouts
E. coli can also spread directly from person to person, such as when an infected person doesn’t wash their hands properly after using the bathroom and then handles food. Once E. coli enters the mouth, you swallow it and it travels down the esophagus to the stomach.
Journey through the digestive system
From the stomach, E. coli moves into the small intestine where it attaches to and colonizes the epithelial cells lining the intestinal wall. The small intestine provides an optimal environment for E. coli to multiply rapidly thanks to the warm temperature, moist surfaces, and abundance of nutrients.
Some strains of E. coli have specialized attachment proteins called intimin that allow them to tightly bind to intestinal epithelial cells. This intimate attachment to the intestinal lining is how certain E. coli strains cause intestinal damage and diarrhea.
As E. coli multiplies in the small intestine, the bacteria and their toxins irritate the intestinal lining. This stimulation triggers the intestine to secrete more fluid and electrolytes, leading to watery diarrhea. Some strains of E. coli also release toxins like Shiga toxin that can damage intestinal cells.
The large intestine
Material passes from the small intestine into the large intestine, carrying E. coli bacteria with it. However, the environment of the large intestine is less hospitable for E. coli growth due to the lack of nutrients and oxygen.
While E. coli prefers the small intestine, it can still survive and even continue to multiply slowly in the large intestine. The bulk of viable E. coli bacteria become concentrated in the final section of the large intestine called the rectum. From there, it’s only a short distance until exiting the body.
E. coli exits the body in feces
E. coli is expelled from your body through the anus in feces. Each gram of human feces contains around 100 million E. coli bacteria.
Diarrhea occurs when excess fluid is secreted into the intestine, speeding up the transit time and resulting in loose, watery stools. This diarrhea helps flush infectious bacteria like E. coli from your body at higher numbers and faster rates than normal.
You can spread E. coli to others if you don’t wash your hands properly after using the toilet and then handle food items. Proper hand washing helps break the fecal-oral route of transmission.
E. coli can survive for a period of time in feces. The bacteria remains infectious at room temperature for up to 12 hours, and can persist longer at colder temperatures.
How long does E. coli last in your body?
For most healthy people, an E. coli infection runs its course in 5-10 days. Your immune system and beneficial gut bacteria work to kill off and expel the infectious bacteria from your intestines.
However, some strains of E. coli can persist in the body for months, especially in young children. The duration depends on factors like:
- Your age and health status
- Virulence of the E. coli strain
- How much of the bacteria you ingested
- Location of infection in your intestines
In most cases, E. coli gets flushed out in your stool within two weeks. But carriers can continue shedding the bacteria for longer without having symptoms.
Treatments help clear E. coli infection
For otherwise healthy people, E. coli infections typically resolve on their own without medication. However, certain treatments can help reduce the duration of infection:
- Hydration – Drinking lots of fluids prevents dehydration from diarrhea and allows you to flush out bacteria faster.
- Antibiotics – Antibiotics may be used for vulnerable populations at risk for severe complications or secondary infections. However, antibiotics can increase Shiga toxin release if used for E. coli O157:H7.
- Anti-diarrheal medication – Medicine like loperamide (Imodium) can help control diarrhea, but should also be used cautiously with E. coli as it may prolong the infection.
Probiotics containing beneficial bacteria may also help crowd out bad bacteria and restore microbial balance to your gut. Talk with your doctor about appropriate symptom relief and treatment options.
Preventing E. coli infection
You can take steps to prevent E. coli from colonizing your intestines in the first place:
- Cook ground beef thoroughly to 160°F and avoid unpasteurized dairy products.
- Wash hands properly after using the bathroom or changing diapers.
- Rinse fruits and vegetables thoroughly before eating.
- Avoid swallowing water when swimming in lakes or pools.
- Take probiotics to support healthy gut flora.
Practicing good hygiene and food safety precautions can block opportunities for E. coli to enter your mouth and travel through your digestive system.
Key Points
- E. coli enters your body by ingesting contaminated food or water, then travels through your digestive tract.
- E. coli colonizes the lining of your small intestine and can cause intestinal damage and diarrhea.
- The bacteria concentrate in the large intestine before exiting your body in feces.
- Infections typically clear within 5-10 days but some strains persist longer.
- Treatments like hydration, antibiotics, and probiotics can help clear E. coli faster.
- Prevent infection by cooking food properly and washing hands well.
Conclusion
E. coli is an intestinal bacterium that is expelled through contaminated feces. E. coli infections spread rapidly and cause symptoms like diarrhea as the bacteria colonize the intestinal lining. However, in most healthy people the infection resolves within two weeks as the bacteria get flushed out through stool. Staying hydrated, taking probiotics, and practicing good hygiene can help clear E. coli infection sooner and prevent transmission. Understanding the journey E. coli takes through your body until exiting in feces can help you minimize the risks from this common bacterium.