How to Prevent and Treat Infectious Colitis

Table of Contents
View All
Table of Contents

Infectious colitis is a contagious illness caused by an infection in the colon, or large intestine. It can be from a virus such as norovirus, a bacterium like Salmonella, or a parasite, and it usually comes from contaminated food or water.

Infectious colitis is usually a short-term condition that just involves at-home symptom management. However, antibiotics are sometimes needed to clear up bacterial infections.

This article looks at types of infectious colitis, its symptoms, how it's diagnosed and treated, your outlook after infection, and how to prevent infectious colitis.

Screening for infectious colitis
Phynart Studio / Getty Images


Infectious colitis can be caused by bacteria, viruses, or parasites.


A large number of cases of infectious colitis are caused by bacteria, specifically food-borne bacteria. Common causes of bacterial colitis include:


Infectious colitis can also be caused by viruses like the cytomegalovirus (CMV). It is a common virus that can be spread through bodily fluids like saliva, blood, urine, semen, and vaginal fluids. It can cause CMV colitis, resulting in inflammation of the stomach and intestines.

Aside from CMV, other viruses that can cause colitis include:

  • Adenovirus, which causes cold-like symptoms
  • Norovirus, which causes vomiting and diarrhea
  • Rotavirus, which causes severe, watery diarrhea in children and infants

Most forms of infectious colitis are contagious and are often transmitted through direct contact with fluids or matter. Infectious colitis could potentially be spread by touching surfaces or objects that are contaminated by these fluids and matter, like a toothbrush. If you start experiencing symptoms like vomiting or diarrhea, contact your healthcare provider.


One common example parasite that can cause colitis is Entamoeba histolytica. Another is the parasite Trypanosoma cruzi (T. cruzi), which leads to Chagas disease, most common in Central America and South America.

Many parasitic infections that cause colitis can be spread through water or food contaminated by infected stools, like Entamoeba histolytica, close personal contact through the rectal area or mouth, or contaminated fertilizer made from human waste.

In the case of T. cruzi, the parasite is most commonly spread through the bite and fecal matter of an insect, the triatomine bug.

Infectious colitis tied to sexually transmitted infections (STIs) disproportionately affect men who have sex with men (MSM), particularly people who are living with human immunodeficiency virus (HIV). These STIs include chlamydia, gonorrhea, and syphilis.


Symptoms of infectious colitis can vary depending on what kind you have. They can include:

  • Bloating, abdominal pain, cramping
  • Bloody or mucus-filled bowel movements
  • Dehydration
  • Diarrhea
  • Headaches
  • Fever
  • Vomiting

When to See a Doctor

If you notice any sudden, drastic shifts in your overall health, you should notify your healthcare provider or seek emergency medical attention immediately. Some warning signs to look for include:

  • Sudden weight loss
  • Dizziness and confusion
  • Changes in urination
  • Presence of blood in your stool or excessive quantities of blood in your stool
  • Changes in your heartbeat
  • Difficulty breathing


Your healthcare provider will provide a routine screening, assessing your past history of infectious colitis. You may also be asked if you have been using any antibiotics and whether you have traveled recently, especially to areas that do not have a clean water supply. Additionally, you'll be questioned about whether you have been admitted to a hospital.

Beyond this, your provider will assess your level of dehydration and take a stool sample to see if you have any viruses, parasites, or bacteria in your system that may be causing your colitis symptoms.

People with sepsis (a life-threatening condition caused by an infection in your body), older adults, and individuals who are immunocompromised may need to go through imaging tests, such as an X-ray or CT (computed tomography) scan. Separately, a colonoscopy (a procedure using a long, flexible tube with a camera attached) may be performed to examine your colon.

What Is Colitis?

The word colitis means inflammation of the colon. Chronic types include Crohn's disease (affects the lining of the small and large intestines) and ulcerative colitis (irritation and ulcers in the colon).

These are forms of inflammatory bowel disease (IBD).


It's important that you focus on hydration. Your healthcare provider will ask you to drink an appropriate amount of liquids. They will let you know what and how much you should be drinking to stay hydrated. You may also be prescribed a hydrating solution that has to be either consumed orally or administered through an IV (an intravenous drip). There will be an emphasis on making sure you load up on electrolytes.

If you have a bacterial infection, you most likely will be prescribed antibiotics, but, again, the dosage, amount, and exact medication will vary depending on the infection and person being treated. Adhere to the recommended dosage, and do not go above or below what your provider prescribes.

Some bacterial infections, like Salmonella don't require antibiotic treatments. A viral colitis infection will require an emphasis on volume of liquid intake. Treatment for parasitic colitis will generally involve hydrating and you might be prescribed a specific medication depending on the infection. Some surgical procedures on the colon, rectum, or surrounding areas may be needed in more serious cases.

Consult with your provider to review the best course of treatment and care as you recover from a case of infectious colitis.


The outlook depends on each individual case. Bacterial, viral, and parasitic cases of colitis can be cured when the appropriate measures are taken. Infectious colitis is not a chronic condition that needs to be managed like Crohn's disease.

How long infectious colitis lasts also differs from person to person. For instance, mild-to-moderate infectious bacterial colitis in children tend to last just one to three days and less than seven days in adults. More severe cases could last for as long as three to four weeks.

Viral colitis should resolve by a one to two weeks if you adhere to the treatment prescribed and focus on rehydrating and resting.

There is no broad, uniform amount of time it takes for parasitic colitis to resolve, but Chagas disease generally resolves within eight weeks.


There are several steps you can take to reduce your risk of contracting infectious colitis. Given that transmission can involve handling food items, it's suggested that you always clean your utensils thoroughly before and after use. You should always keep raw and cooked foods separate and avoid eating undercooked items.

Also be aware of the water you drink. Avoid taking in water from swimming pools and bodies of waters like lakes. When you are traveling, rely on bottled water, but still make sure you know where the water is coming from and whether it's clean.

You should also wash your hands frequently to avoid the spread of germs. If you notice any sudden changes in your health or are concerned that you may have been exposed to an infection, contact your healthcare provider.

A Word From Verywell

Infectious colitis, whether viral, bacterial, or parasitic, can be a serious condition. It can lead to weight loss, digestive problems, bloating, fever, and more severe illness. As with any infection, it's important to prevent its spread. Be mindful of what you are eating and drinking when traveling, and always practice proper hygiene to prevent the spread of germs.

If you notice abrupt changes in your health or are concerned about potential symptoms, contact your healthcare provider right away.

Frequently Asked Questions

  • What are the symptoms of infectious colitis?

    Symptoms of infectious colitis vary case by case. They can include bloody and mucus-filled bowel movements, diarrhea, dehydration, headaches, vomiting, fever, as well as bloating and abdominal pain. If you experience sudden shifts in your health or persistent, chronic symptoms, please consult your healthcare provider right away.

  • How long does it take to recover from infectious colitis?

    Recovery depends on the severity of infection and the type of infection. Some mild-to-moderate cases in children can last for up to three days, while it is evidenced in adults less than a full week. More serious cases can last for up to four weeks.

  • What is infectious colitis?

    Colitis refers to inflammation of your large intestine, also known as the colon. This inflammation can be caused by viral, bacterial, or parasitic infections. Treatment of these infections varies depending on the specific case. Your healthcare provider will devise a course of treatment that will generally focus on rehydration, rest, and in some instances, medication and antibiotics if it's a bacterial infection.

  • Is infectious colitis contagious?

    Infectious colitis can be highly contagious. Types of infectious colitis can be passed when you come into contact with fecal matter or fluids. Some forms of infectious colitis are tied to sexually transmitted infections (STIs).

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Emergency Care Institute (ECI) of New South Wales. Infectious colitis.

  2. MedlinePlus. CMV - gastroenteritis/colitis.

  3. Absah I, Faubion W. Severe colitis associated with rotavirus in a child with CUC: P-26Inflammatory Bowel Diseases. 2011;17(Suppl_2):S19-S19. doi:10.1097/00054725-201112002-00063

  4. Scordino D. Infectious Colitis. Oxford University Press. doi: 10.1093/med/9780199976805.001.0001

  5. Hechenbleikner EM, McQuade JA. Parasitic colitisClin Colon Rectal Surg. 2015;28(2):79-86. doi:10.1055/s-0035-1547335

  6. MedlinePlus. Amebiasis.

  7. Arnold CA, Roth R, Arsenescu R, et al. Sexually transmitted infectious colitis vs inflammatory bowel disease: distinguishing features from a case-controlled studyAmerican Journal of Clinical Pathology. 2015;144(5):771-781. doi:10.1309/AJCPOID4JIJ6PISC

  8. The George Washington University Hospital. Colitis.

  9. Penn Medicine. Colitis.

  10. Ackman D, Marks S, Mack P, Caldwell M, Root T, Birkhead G. Swimming-associated haemorrhagic colitis due to Escherichia coli O157:H7 infection: evidence of prolonged contamination of a fresh water lakeEpidemiol Infect. 1997;119(1):1-8. doi:10.1017/s095026889700770x

  11. Centers for Disease Control and Prevention (CDC). Water treatment options when hiking, camping or traveling.

By Brian Mastroianni
Brian Mastroianni is a health and science journalist based in New York. His work has been published by The Atlantic, The Paris Review, CBS News, The TODAY Show, Barron's PENTA, Engadget and Healthline, among others.