Diarrhea & Intestinal Parasites

Diarrhea is a common urgent care complaint. Most of these patients will have a diarrhea of unknown origin, presumably of viral origin. We almost never see intestinal parasites when we work up patients with diarrhea. Since most are viral and no treatment except supportive is indicated, when should you be concerned enough to seek medical help?

If the patient is afebrile with mild diarrhea, we employ OTC Immodium. One or two tablets usually will slow stooling to tolerable limits. We do not culture the stool on these patients. However, there are conditions that suggest a bacterial or parasitic infection may be present:
• Recent trip to Mexico, South America, Asia, or areas with poor sanitation
• Prolonged diarrhea-2 or more weeks
• Fever and blood in the stools
• Recent seafood ingestion, especially shellfish
• Immunocompromised status-AIDS, chemotherapy
• Other people with similar illness
• Prior use of antibiotics in last month
• Sexual history

If any of the above is relevant, we obtain a stool for culture, WBC’s (inflammatory cells), Giardia antigen, and microscopic exam for parasites. In very rare cases, colon examination is necessary.

Contaminated food can be the source. Cheeses and shellfish have been incriminated, but almost any food can be responsible. A recent course of an antibiotic may cause an overgrowth of C. dificile and diarrhea. Hiking in the mountains and drinking the water is a source for giardia.

Parasites are uncommon, except for giardia and pinworms (children). A therapy directed at bowel cleansing with “high colonics” is supposed to flush our all the parasites, but is would be ineffective and not appropriate. At our center for examining the colon-colonoscopy with direct visualization, we have seen only one worm in 15 years of operation. Parasites in the USA are confined to immigrants. In other parts of the world, they can be common.

Read more about Diarrhea & intestinal parasites:

http://digestive.niddk.nih.gov/ddiseases/pubs/diarrhea/
www.iffgd.org
www.intestinalfoundation.org
www.eatright.org

Written & edited by Robert E. Dyer, MD