St. Luke's Hospital
Located in Chesterfield, MO
Main Number: 314-434-1500
Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
Find a Physician Payment Options Locations & Directions
Follow us on: facebook twitter Mobile Email Page Email Page Print Page Print Page Increase Font Size Decrease Font Size Font Size
Meet the Doctor
Spirit of Women
Community Health Needs Assessment
Home > Health Information

Multimedia Encyclopedia



    Amebic dysentery; Intestinal amebiasis

    Amebiasis is an infection of the intestines caused by the parasite Entamoeba histolytica.


    Entamoeba histolytica can live in the large intestine (colon) without causing damage to the instestins. However, sometimes, it invades the colon wall, causing colitis, acute dysentery, or long-term (chronic) diarrhea. The infection can also spread through the blood to the liver and, rarely, to the lungs, brain, or other organs.

    This condition occurs worldwide, but it is most common in tropical areas with crowded living conditions and poor sanitation. Africa, Mexico, parts of South America, and India have significant health problems associated with this disease.

    Entamoeba histolytica is spread through food or water contaminated with stools. This contamination is common when human waste is used as fertilizer. It can also be spread from person to person -- particularly by contact with the mouth or rectal area of an infected person.

    Risk factors for severe amebiasis include:

    • Alcoholism
    • Cancer
    • Malnutrition
    • Older or younger age
    • Pregnancy
    • Recent travel to a tropical region
    • Use of corticosteroid medication to suppress the immune system

    In the United States, amebiasis is most common among those who live in institutions or people who have returned from travel to an area where amebiasis is common.


    Most people with this infection do not have symptoms. If symptoms occur, they are seen 7 to28 days after being exposed to the parasite.

    Mild symptoms:

    • Abdominal cramps
    • Diarrhea
      • Passage of 3 - 8 semiformed stools per day
      • Passage of soft stools with mucus and occasional blood
    • Fatigue
    • Excessive gas
    • Rectal pain while having a bowel movement (tenesmus)
    • Unintentional weight loss

    Severe symptoms:

    • Abdominal tenderness
    • Bloody stools
      • Passage of liquid stools with streaks of blood
      • Passage of 10 - 20 stools per day
    • Fever
    • Vomiting

    Exams and Tests

    Examination of the abdomen may show liver enlargement or tenderness in the abdomen.

    Tests include:

    • Blood test for amebiasis
    • Examination of the inside of the lower large bowel (sigmoidoscopy)
    • Stool test
    • Microscope examination of stool samples, usually over several days


    Treatment depends on the severity of infection. Usually, metronidazole is given by mouth for 10 days. This is followed by paromomycin or diloxanide.

    If you are vomiting, you may need to medications through a vein (intravenously) until you can take them by mouth.Medicines to stop diarrheaare usually not prescribed because they can make the condition worse.

    After treatment, the stool should be rechecked to make sure that the infection has been cleared.

    Outlook (Prognosis)

    The outcome is usually good with treatment. Usually, the illness lasts about 2 weeks, but it can come back if treatment is not given.

    Possible Complications

    • Liver abscess
    • Medication side effects, including nausea
    • Spread of the parasite through the blood to the liver, lungs, brain, or other organs

    When to Contact a Medical Professional

    Call your health care provider if you have persistent diarrhea.


    When traveling in tropical countries where poor sanitation exists, drink purified or boiled water and do not eat uncooked vegetables or unpeeled fruit. Public health measures include water purification, water chlorination, and sewage treatment programs.


    Petri WA Jr, Haque R. Amebiasis. In: Goldman L, Schafer AI,eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 360.

    Petri WA Jr, Haque R. Entamoeba species, including amebiasis.In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 273.


    • Amebic brain abscess


    • Digestive system


    • Digestive system organs


      • Amebic brain abscess


      • Digestive system


      • Digestive system organs


      Tests for Amebiasis

        Review Date: 8/15/2012

        Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.

        The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

        A.D.A.M. content is best viewed in IE9 or above, Fire Fox and chrome browser.

        Back  |  Top
        About Us
        Contact Us
        Locations & Directions
        Quality Reports
        Annual Reports
        Honors & Awards
        Community Health Needs

        Brain & Spine
        Sleep Medicine
        Urgent Care
        Women's Services
        All Services
        Patients & Visitors
        Locations & Directions
        Find a Physician
        Tour St. Luke's
        Patient & Visitor Information
        Contact Us
        Payment Options
        Financial Assistance
        Send a Card
        Mammogram Appointments
        Health Tools
        My Personal Health
        Spirit of Women
        Health Information & Tools
        Clinical Trials
        Employer Programs -
        Passport to Wellness

        Classes & Events
        Classes & Events
        Spirit of Women
        Donate & Volunteer
        Giving Opportunities
        Physicians & Employees
        For Physicians
        Remote Access
        Medical Residency Information
        Pharmacy Residency Information
        Physician CPOE Training
        St. Luke's Hospital - 232 South Woods Mill Road - Chesterfield, MO 63017 Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
        Copyright © St. Luke's Hospital Website Terms and Conditions  |  Privacy Policy  |  Notice of Privacy Practices PDF  |  Patient Rights PDF Sitemap St. Luke's Mobile