saudigastro.com/patients/amoebiasis
Category
Common
Red flags
4
This article is educational and does not replace your doctor's advice. Seek urgent care for any red-flag symptoms.
What is it?
Amoebiasis is an infection caused by a single-celled parasite called Entamoeba histolytica. The parasite lives in the large bowel (colon). Many people carry it without any symptoms. In others it invades the bowel wall and causes inflammation and ulcers, known as amoebic dysentery (diarrhea with blood and mucus). Rarely, the parasite travels through the blood to the liver and forms a collection of pus called an amoebic liver abscess.
How common is it?
The infection is more common in places where sanitation and clean drinking water are limited, and among people who travel to or live in such areas. Many infected people never become ill. Severe disease is much less common than mild or silent infection.
Why does it happen?
The parasite is passed in the stool of an infected person as tiny hardy forms called cysts. You become infected by swallowing cysts in food or water contaminated with stool, for example unwashed raw vegetables or fruit, untreated water, or food handled with unwashed hands. It can also spread through close contact with an infected person when hand washing is poor.
Symptoms
- Diarrhea that may contain blood or mucus
- Cramping abdominal pain
- Painful urge to pass stool (tenesmus) with a feeling of incomplete emptying
- Gas, bloating and loss of appetite
- Tiredness and weight loss if symptoms last for weeks
- Fever, and pain in the upper right abdomen if the liver is involved
Red flags — seek urgent medical care
Heavy bloody diarrhea or signs of dehydration (very dry mouth, dizziness, passing little urine)
You may be losing too much blood or fluid. Go to the emergency department.
Severe or constant abdominal pain, a hard swollen belly, or high fever
This may mean a serious bowel complication. Seek emergency care now.
Fever with pain in the upper right abdomen, especially after diarrhea
Possible liver abscess. Needs urgent medical assessment.
Diarrhea in a young child or elderly person that does not improve or causes drowsiness
Dehydration develops quickly in these groups. Take them to be seen immediately.
How is it diagnosed?
Your doctor will ask about travel, water and food exposure. Stool tests look for the parasite or its genetic material or proteins; sometimes several samples are needed because the parasite can be missed. Blood tests can show antibodies, which help especially when a liver abscess is suspected, and ultrasound or CT scan can show a liver abscess. Colonoscopy is not usually needed but may be used if the diagnosis is unclear, and it can look like inflammatory bowel disease, so correct diagnosis matters before starting steroid treatment.
Outlook — what to expect
With proper treatment most people recover fully. Treatment usually has two steps: a medicine to kill parasites in the bowel wall and tissues, followed by a second medicine to clear parasites remaining in the bowel. Liver abscess also generally responds well to medicines, sometimes with drainage. Re-infection is possible if exposure continues.
Treatment
Habits & Lifestyle
Good hygiene prevents spread and re-infection.
- Wash hands with soap and water after using the toilet and before preparing or eating food.
- Rest and drink plenty of fluids while you have diarrhea.
- Avoid preparing food for others until your doctor confirms you are no longer infectious.
- Do not share towels, and clean toilet surfaces regularly during the illness.
Diet
Food does not cure the infection, but it helps you stay hydrated and comfortable.
- Drink safe water, and use oral rehydration solution if you have watery diarrhea.
- Eat small light meals as tolerated; return to a normal diet as you recover.
- Wash raw vegetables and fruit well with safe water, or peel them.
- When travelling to areas with poor sanitation, drink bottled or boiled water and avoid ice of unknown source.
Medications
Amoebiasis needs prescription medicines. Do not treat it yourself.
- Your doctor will prescribe an anti-parasitic antibiotic that acts in the tissues, followed by a second medicine that clears parasites from inside the bowel.
- Finish the full course even if you feel better.
- Some of these medicines cause nausea or a metallic taste, and alcohol should be avoided while taking them; ask your doctor or pharmacist.
- Do not take anti-diarrhea medicines such as loperamide unless your doctor says so, as they can make bloody infection worse.
Procedures & Surgery
Most people do not need a procedure.
- A liver abscess that is large or does not improve with medicines may need to be drained with a needle or small tube guided by ultrasound or CT.
- Surgery is rarely needed and is reserved for severe bowel complications such as perforation.
- Colonoscopy may be used to confirm the diagnosis in unclear cases.
Living with the condition
- Complete your follow-up stool tests if your doctor requests them.
- Household members with diarrhea should also be assessed.
In the Saudi context
Pilgrims and travellers, and people returning from countries with limited sanitation, should be careful with water and raw foods, and should seek medical advice for diarrhea that is bloody or lasts more than a few days.
Questions to ask your doctor
Save this list or print it before your appointment — doctors appreciate prepared patients.
- Which test confirms that I have amoebiasis and not another bowel disease?
- Do I need the second medicine to clear the bowel?
- Should my family members be tested?
- When is it safe to return to work or to prepare food?
- How can I avoid getting it again when I travel?
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Status: Approved for publication by SGA; individual clinician review is ongoing · Published 24/04/2026
For general education only; it does not replace your doctor’s advice. Individual clinician review of this guide is ongoing. SGA clinician? Review this guide