Intestinal Protozoal Diseases Treatment & Management

Updated: Sep 21, 2022
  • Author: Enrique Chacon-Cruz, MD, MSc; Chief Editor: Russell W Steele, MD  more...
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Medical Care

The most important aspect of providing care for children with diarrhea caused by intestinal protozoa includes standard pediatric assessments.

Evaluate the child for signs of dehydration, including tachycardia, delayed capillary refill, decreased tears, decreased activity, decreased urine output, and altered mental status.

Hypovolemic shock rarely occurs with these infections but must be recognized.

The child must be evaluated for the adequacy of the nutritional status. This is particularly important in cases of chronic diarrhea and possible immunodeficiency.

Weight must be measured and compared on the growth curve. Appropriate interventions occur following this immediate assessment.

Oral rehydration therapy (ORT) is the preferred approach for children with mild-to-moderate dehydration. Intravenous rehydration should rarely be necessary. Current recommendations for pediatric rehydration are outlined best in The Management of Acute Diarrhea in Children: Oral Rehydration, Maintenance, and Nutritional Therapy. [24]

Following immediate fluid resuscitation for dehydration, the clinician must address potential nutritional issues and provide adequate nutrition to the child with acute or chronic diarrhea.

Protozoal GI infections in immunocompetent patients are usually mild-to-moderate self-limited diseases, and special precautions are not needed.

The hallmark for treatment of these diseases is specific antiprotozoal therapy.

Patients with severe amebic or balantidic colitis should not receive oral nutrition and should be monitored for potential surgical complications.

Consider parenteral nutrition in some patients.

Patients with amebic liver abscess should be treated in the hospital until potential complications have been ruled out.


Surgical Care

Only 2 well-recognized conditions in which surgical therapy is necessary for intestinal protozoal diseases are known: necrotizing colitis, caused by E histolytica or B coli, and complicated amebic liver abscess.

  • Indications for surgery in fulminant amebic colitis include the following:

    • Failure to respond to antiamebic drugs following perforation and localized abscess formation

    • Persistence of abdominal distension and tenderness despite effective antiamebic therapy

    • Toxic megacolon

  • Partial colectomy with colostomy is recommended over primary anastomosis for localized colonic disease because an anastomosis may be incompetent because of the friable condition of the affected intestinal wall.

  • For extensive disease, better surgical results have been obtained with total colectomy with exteriorization of the proximal and distal ends.

  • Indications for needle aspiration in amebic liver abscess include the following:

    • Rupture to pleura, pericardium, or both

    • Left lobe abscesses and proximity to the pericardium

    • As a diagnostic procedure when a pyogenic abscess is highly suspected

    • When surgical drainage is indicated because of imminent rupture of the abscess to the peritoneal cavity or presence of necrotizing colitis

    • When, in some cases, perianal fistulization of intestinal amebic foci is present and necessitates surgical drainage



The primary care physician can manage the vast majority of cases of gastroenteritis associated with protozoal infections. These infections rarely result in complications requiring hospitalization.

In patients with chronic diarrhea or amebic liver abscess, consultation with a gastroenterologist along with an infectious-disease specialist may be useful.

Surgeons should be consulted when the patient is suspected to have necrotizing colitis, complicated amebic liver abscess, or both.

Nutritional support may also be beneficial in severe cases.


Diet and Activity


In immunocompetent patients, effective antiprotozoal therapy results in full recovery.

Some patients with severe giardiasis may experience disaccharidase deficiency and may require lactose-free diets, but this is a temporary condition that usually does not last more than 2 weeks.

Patients with AIDS and severe spore-forming protozoal infections (chronic diarrhea with wasting syndrome) require hypercaloric diets. This is indicated for the protozoal illness in addition to the wasting syndrome associated with the underlying disease.

For amebic liver abscess, some experts recommend a low-fat diet during antiamebic treatment, but no clinical trials have examined the effects of this diet on the patient's outcome.


The only limitations for physical activity are in patients with amebic liver abscess who may require hospitalization and patients who require surgery for necrotizing colitis.