Review Article | Published:

Beyond O&P Times Three

The American Journal of Gastroenterologyvolume 113pages805818 (2018) | Download Citation



Although examination of the stool for ova and parasites times three (O&P ×3) is routinely performed in the United States (US) for the evaluation of persistent and/or chronic diarrhea, the result is almost always negative. This has contributed to the perception that parasitic diseases are nearly non-existent in the country unless there is a history of travel to an endemic area. The increasing number of immigrants from third-world countries, tourists, and students who present with symptoms of parasitic diseases are often misdiagnosed as having irritable bowel syndrome or inflammatory bowel disease. The consequences of such misdiagnosis need no explanation. However, certain parasitic diseases are endemic to the US and other developed nations and affect both immunocompetent and immunocompromised patients. Testing for parasitic diseases either with O&P or with other diagnostic tests, followed by the recommended treatment, is quite rewarding when appropriate. Most parasitic diseases are easily treatable and should not be confused with other chronic gastrointestinal (GI) disorders. In this review, we critically evaluate the symptomatology of luminal parasitic diseases, their differential diagnoses, appropriate diagnostic tests, and management.

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  1. Department of Internal Medicine, Saint Peter’s University Hospital – Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA

    • Sonmoon Mohapatra MD
    •  & Dhruv Pratap Singh MBBS
  2. Department of Infectious Diseases, Saint Peter’s University Hospital – Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA

    • David Alcid MD
  3. Department of Gastroenterology, Hepatology and Clinical Nutrition Saint Peter’s University Hospital – Rutgers Robert Wood Johnson School of Medicine, New Brunswick, NJ, USA

    • Capecomorin S Pitchumoni MD


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SM wrote the paper with the help of other co-authors. DPS analyzed the literature for the tables. DA reviewed the paper for scientific accuracy. CSP formulated the idea, structure and the content for the paper.

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