There are two main types of intestinal parasites, according to Dr. Leo Galland in an article for the Huffington Post. Worm-type parasites mainly rob the body of nutrients and can cause anemia but few other symptoms. The other type includes organisms such as Giardia, which lead to a number of acute symptoms, especially gastrointestinal discomfort.
Look for symptoms such as chronic diarrhea, abdominal pain, bloating, and nausea and vomiting. If you can’t identify a cause for these symptoms and they seem to keep coming back on a regular basis, they could indicate the presence of intestinal parasites.
Pay attention to your bowel movements. It’s possible to pass a worm in the stool and you might also experience itching around the rectal area.
Investigate unexplained weight loss and lethargy. These can occur if you’ve had intestinal parasites for a long time. Chronic fatigue can sometimes be caused by intestinal parasites.
Ask your doctor for a stool test. Not all parasites produce obvious symptoms, so you might have intestinal parasites for years and never realize it. More invasive tests, such as a proctoscopy, are sometimes needed.
Talk to your doctor if you experience a combination of these symptoms after a trip to a third-world country, a stay or long periods of work at an institutional care center, or a visit to any area with poor sanitation. Intestinal parasites thrive in these areas and your risk of exposure is higher.