Could You Have an Intestinal Parasite?

If you've been experiencing stomach pain, diarrhea, and fatigue, you may have an intestinal parasite. There are two main types of intestinal parasites: helminths, which are worms (tapeworms, pinworms, and roundworms are the most common), and protozoa, which have only one cell and can multiply inside the body, allowing serious infections to develop. The most common types of protozoa in the United States are giardia lamblia and cryptosporidium. Intestinal parasites are fairly common and can be serious, especially in the elderly, people living in undeveloped countries, and those who have other health problems.

Causes of Intestinal Parasites

Intestinal parasites are usually contracted by contact with infected feces, through contaminated soil, food, or water. Soil that is fertilized with human or animal waste may contain hookworms, which can enter the body through small cuts or abrasions and infect the intestines. Other causes of intestinal parasites include:

  • Poor sanitary conditions in food or water
  • Undercooked or raw foods
  • Water contaminated with human or animal feces.
  • Walking through mud or puddles without proper footwear
  • Swimming in a contaminated creek, river, or lake.
  • A weakened immune system
  • Contact with infected animals


Often there are no intestinal parasite symptoms. However, when parasites start becoming troublesome symptoms may include:

  • Abdominal pain
  • Bloating or gas
  • Nausea, vomiting
  • Diarrhea, which may become severe and chronic
  • Dysentery (loose stools containing blood and mucus)
  • Weight loss
  • Fatigue
  • Passing a worm in your stool

If you're experiencing these problems, make an appointment to see your doctor. If your doctor thinks you may have an intestinal parasite, she will likely order a series of tests including:

  • Fecal testing (an examination of your stool) to identify the type of parasite you have.
  • The Scotch tape test in which tape is applied around the anus and then examined under a microscope for parasitic eggs.
  • A barium solution, followed by a series of x-rays to look for more serious parasitic damage.

Once your doctor has determined the exact type of parasite you have, she will prescribe a medication that is most effective against the organism. Then she will test your stool again following treatment to make sure the parasite is gone.