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Overview

What Is Infectious Colitis?

Infectious colitis is inflammation of the colon caused by an infection. Bacteria, viruses or parasites can irritate the colon and lead to diarrhea and other digestive symptoms. This colitis definition includes illnesses that may be mild and short-lived or severe enough to cause dehydration and other complications. Anyone can develop infectious colitis, although some people have a higher risk of serious illness.

Symptoms

Symptoms of Infectious Colitis

  • Diarrhea (frequent or loose stools).
  • Abdominal cramping (painful muscle spasms).
  • Abdominal pain.
  • Fever (elevated body temperature).
  • Nausea (feeling sick to your stomach).
  • Vomiting (throwing up).
  • Blood or mucus in the stool (rectal bleeding or intestinal mucus).

Seek prompt care

Know the warning signs

Severe dehydration, bloody diarrhea, persistent vomiting, severe abdominal pain or a high fever requires prompt medical assessment. These colitis symptoms may indicate a serious infection or complication.

How It Spreads

How Infectious Colitis Spreads

Infectious colitis can spread when germs pass from stool to the mouth, known as fecal-oral transmission. This may happen through contaminated food or water, unwashed hands or close contact with an infected person. Some cases are associated with healthcare settings or recent antibiotic use, but not every infection spreads in the same way. The route depends on the organism involved and the person’s exposure.

FOOD AND WATER

Contaminated food or water
Food or drinking water contaminated with infectious organisms can carry them into the digestive tract.

PERSON TO PERSON

Close contact
Poor hand hygiene and close contact can spread some infections between people.

HEALTHCARE OR ANTIBIOTICS

C. difficile exposure
Some C. difficile infections occur after antibiotic exposure or contact with healthcare environments and can cause pseudomembranous colitis.

Risk Factors

Risk Factors for Infectious Colitis

  • Recent antibiotic use can increase the risk of some infections, including C. difficile.
  • Exposure to a hospital, healthcare facility or long-term-care setting can increase exposure to infectious organisms.
  • A weakened immune system can make infection more likely or more severe.
  • Travel to an area with unsafe food or water can increase exposure risk.
  • Poor sanitation can increase contact with germs that cause infectious colitis.
  • Eating contaminated food or drinking contaminated water can transmit infection.
  • Older adults and very young children have a higher risk of severe illness.

Complications

Complications of Infectious Colitis

  • Dehydration can occur when diarrhea and vomiting cause excessive fluid loss.
  • Electrolyte imbalance can affect muscles, nerves and heart function.
  • Kidney injury can develop when severe dehydration reduces blood flow to the kidneys.
  • Bloodstream infection (sepsis) can occur if infection spreads beyond the intestine.
  • Toxic megacolon is a rare, severe widening of the colon caused by intense inflammation.
  • C. difficile infection can recur after an initial episode.

Urgent warning signs

Get help for severe symptoms

Seek urgent medical care for confusion, fainting, inability to keep fluids down, very little urination, severe abdominal swelling or pain, or bloody stools. These signs can indicate dehydration, severe intestinal inflammation or illness affecting the whole body.

Diagnosis

How Infectious Colitis Is Diagnosed

To diagnose infectious colitis, a clinician considers the symptom pattern and duration, recent antibiotic use, travel, food exposures, contact with sick people and your medical history. A physical examination can help assess abdominal tenderness, dehydration and other signs of illness. These details help distinguish infection from other causes of colitis.

STOOL TESTING

Find the cause
Stool tests can identify organisms or toxins that may guide treatment.

BLOOD TESTS

Assess severity
Blood tests can assess inflammation, infection severity and fluid or electrolyte problems.

IMAGING OR ENDOSCOPY

Investigate complicated illness
Imaging or colonoscopy is used selectively when illness is severe, persistent or atypical, or when complications or another diagnosis is suspected.

Treatment & Management

Infectious Colitis Treatment and Management

Supportive care is central to colitis treatment and may include oral fluids, intravenous fluids when needed, electrolyte replacement, rest and appropriate nutrition. Severe dehydration or complications may require hospital care. Treatment decisions depend on the suspected or identified pathogen, the severity of illness and the person’s overall health.

Explain when targeted treatment is used

  • Antibiotics may be used for selected bacterial infections when a clinician determines that they are appropriate.
  • Antiparasitic medicines may be used when testing or clinical assessment supports a parasitic infection.
  • Other targeted therapies depend on the organism, test results and severity of illness.
  • Some antibiotics can cause or worsen C. difficile infection, so they should not be used without medical guidance.

Medication safety

Ask before using antidiarrheal medicine

Ask a clinician before using antidiarrheal medicines, especially if you have fever, bloody stools, suspected C. difficile or severe illness. These medicines may not be safe or appropriate in every infection.

Prevention

How to Prevent Infectious Colitis

  • Wash your hands thoroughly with soap and water after using the bathroom and before preparing or eating food.
  • Prepare and store food safely by cooking it thoroughly and preventing cross-contamination.
  • Drink safe water and avoid water from uncertain sources.
  • Avoid sharing towels and other personal items while someone is ill.
  • Clean and disinfect surfaces contaminated by stool or vomit.
  • Take antibiotics only as prescribed and do not save or share them.

Outlook and Prognosis

Outlook and Prognosis

Many cases of infectious colitis improve with hydration and appropriate care. Recovery time varies depending on the pathogen, the severity of illness and the person’s overall health. Some infections can recur or cause symptoms that last longer than expected, so persistent diarrhea or worsening symptoms should be reassessed. An acute colitis illness does not always follow the same course from person to person.

When Should You See a Doctor

When Should You See a Doctor?

  • Contact a clinician promptly for severe or persistent diarrhea.
  • Seek medical advice for blood or black stool.
  • Contact a clinician for a high fever or significant abdominal pain.
  • Seek care for repeated vomiting or difficulty replacing lost fluids.
  • Contact a clinician if symptoms begin after recent antibiotic use.
  • Seek medical advice if symptoms affect an older adult, young child, pregnant person or someone with a weakened immune system.

Get urgent help

Know when it is an emergency

Go to emergency care for fainting, confusion, severe dehydration, inability to keep fluids down, severe abdominal swelling or pain, or rapidly worsening illness. These symptoms may signal a serious complication of infectious colitis.

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