Can Parasites Cause IBS?

Irritable bowel syndrome (IBS) is a condition that can cause symptoms like stomach pain and changed bowel movements. Intestinal parasites can cause very similar symptoms. Additionally, there can be a link between parasites and IBS.^1,2

What are intestinal parasites?

Intestinal parasites are things that use your intestines for food and shelter. They can be worms or single-celled organisms called protozoa. Having parasites can cause uncomfortable symptoms and can sometimes lead to serious health risks such as dehydration, malnutrition, and bowel obstruction.^1,2

Intestinal parasites usually spread when people accidentally eat their eggs. This can happen if you eat contaminated water or food. The eggs can also live on surfaces. Touching your mouth if your hands have eggs on them can also spread parasites.¹

Symptoms of parasite infections

Symptoms of parasite infections can be very similar to IBS symptoms. In some cases, it can be difficult to tell the difference when diagnosing the 2 conditions. Symptoms of parasite infections may include:^1,3

• Diarrhea
• Stomach pain
• Gas and bloating
• Nausea and vomiting

Do parasites cause or contribute to IBS?

The symptoms of IBS and intestinal parasites can be very similar. Additionally, intestinal parasites may cause IBS in some people. This is called postinfection IBS or PI-IBS. It is not clear why parasites can cause IBS. Some possible links include:^2,3

Parasites can cause long-term inflammation in the intestines. This inflammation may cause IBS.
Parasites may cause bacteria to grow in the intestines. The bacteria then can impact gut health.

Research on parasites and IBS is limited. But it seems that there is more likely to be a link between IBS and protozoa than worms. Some research also suggests that IBS is a risk factor for parasites. That means people with IBS are more likely to be affected by parasites.^2,3

PI-IBS treatment

Before treating PI-IBS, you have to make sure you have treated the parasite. Diagnosing and treating parasites early can prevent the risk of PI-IBS. There are many antiparasitic drugs that can clear the infection effectively.^1,3

After treating the parasite, treatment for PI-IBS is similar to standard IBS treatment. Some research has found treatments that may work especially well for PI-IBS. However, these results are not confirmed. Treatments to help PI-IBS may include:^3-5

• Diet changes. For example, some people struggle to digest foods with FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). A low FODMAP diet avoids these types of foods.
• Steroids, such as prednisone.
• Mesalazine, which is a drug for many different gastrointestinal conditions.
• Glutamine, which is an amino acid that impacts digestion.

Returning to gut health after a parasite infection

It is possible that the link between IBS and parasites is related to gut health. This could mean that working on your gut health can help lower the risk of PI-IBS. For example, the low FODMAP diet is linked to gut health. Other steps that may help with gut health include:^2-4

• Eating a healthy diet with lots of fiber.
• Eating smaller meals.
• Avoiding drinks with caffeine.

These steps will not work for everyone with IBS or parasite infections. Talk with your doctor about the best ways to keep your gut healthy.^1,2