Amoebiasis, Amebic Dysentery, Entamebiasis

Basic Information

What is Amebiasis?

A parasitic infection of the large intestine and sometimes the liver. Amebiasis is found worldwide, but is most prevalent in developing countries. In the USA, the disease is relatively rare in the general population, but is concentrated in some high-risk groups. Many people, especially those who live in temperate climates, harbor the amoeba without symptoms. Symptoms occur when the parasite invades tissues of the colon. Symptoms may be very vague.

Amebiasis signs and symptoms

  • Sometimes no symptoms are present.
  • Intermittent diarrhea with bad-smelling stools. Diarrhea is often preceded by constipation in early stages.
  • Gas and abdominal bloating.
  • Abdominal cramps and tenderness.
  • Fever.
  • Mucus and blood in the stool (sometimes).
  • Fatigue.
  • Muscle aches.
If the liver is involved:
  • Tenderness over the liver and right side of the abdomen.
  • Yellow skin or eyes (sometimes).
  • Shaking chills.
  • Weight loss.


A microscopic parasite, Entamoeba histolytica, that is spread by flies, cockroaches and direct contact with hands or food contaminated with feces. The most common sources of infection are:

  • Infected food handlers.
  • Faulty hotel or factory plumbing.
  • Raw vegetables or fruit fertilized with human feces or washed in polluted water.

Risk increases with

  • Crowded or unsanitary living conditions.
  • Travel to a foreign country.
  • Combination of anal-oral sex.
  • Institutional living.

Preventive measures

  • Wash your hands frequently and always before eating.
  • If you are in an area where food or water may be contaminated, the following measures are necessary:
    • Boil drinking water for 5 minutes.
    • Don't use tap water for brushing teeth and be careful not to swallow water when showering.
    • Don't eat unpeeled fruit or vegetables, raw fish or shellfish, or any questionable dairy products (ice cream, milk, butter, etc.).

Expected outcomes

In most cases without complications, amebiasis is curable in 3 weeks with treatment. In the carrier state, this disease may not cause any symptoms. In severe cases, it may cause dysentery that requires hospital treatment.

Possible complications

  • Peritonitis.
  • Hepatitis or liver abscess.
  • Lung abscess.
  • Infection of the pericardium.
  • Brain abscess.

Amebiasis treatment

General measures

  • Diagnostic tests may include laboratory studies of stool specimens and blood samples; if liver involvement is suspected, CT scan or ultrasound and biopsy may be necessary.
  • Be extra careful about personal cleanliness. Bathe frequently, and wash hands with warm water and soap after each bowel movement and before handling food.
  • In the case of a liver abscess, surgery may be necessary.

Additional Information


  • Metronidazole or iodoquinol (or both), paromomycin, or diloxanide may be prescribed.
  • Fluid replacement may be necessary to manage electrolyte imbalance due to diarrhea.
Flagyl (Metronidazole)


Rest in bed during an acute attack. Resume normal activities when fever disappears and diarrhea improves.


Soft diet progressing to normal diet.

Notify your physician if

  • You or a family member has symptoms of amebiasis.
  • The following occur during treatment:
    • Abdominal cramps continue longer than 24 hours.
    • Diarrhea or blood in stool increases.
    • Vomiting begins.
    • Pain begins over liver or jaundice (yellow skin or eyes) occurs.
    • A skin rash appears.
    • Irritability or a severe headache develop.