Pin Me

Signs and Symptoms of Intestinal Parasites

written by: N Nayab • edited by: Emma Lloyd • updated: 5/24/2011

Most of the symptoms of intestinal parasites in humans manifest as disorders related to the stomach, skin, and central nervous system.

  • slide 1 of 7

    Intestinal Parasites A parasite survives by hijacking another organism, robbing it of its nutrients, and leaving behind toxic waste. Human intestinal parasites in the form of single celled protozoa and multi-celled helminthes work on the same principle.

    Many of the intestinal parasites in humans are harmless and reside within humans for years without generating any symptoms. For the harmful category, many people do not recognize the signs and symptoms of intestinal parasites because either the signs manifest after a long time or they mimic the symptoms of some other diseases.

    Image Credit:

  • slide 2 of 7

    Symptoms of Intestinal Parasites Related to Bowels

    The most common symptoms of intestinal parasites in humans manifest as disorders related to the stomach, such as irritable bowel syndrome, constipation, vomiting, diarrhea, gas, and bloating.

    • Irritable Bowel Syndrome: Irritable bowel syndrome usually occurs in the absence of parasitic disease, but it also ranks amongst the most common symptoms of intestinal parasite. Certain parasites dig in and attach themselves to the walls of the colon and intestines, causing irritation and inflammation. This leads to muscle spasm, gastrointestinal symptoms, intestinal blockage, and inefficient absorption of nutrients, especially when consuming fatty substances. All these situations cause bulky stools and build up of fecal matter in the colon and intestines.
    • Constipation: Intestinal parasite worms cause constipation when they grow large enough and physically block the passage of nutrients and waste at certain points in the digestive system. Such large worms in bile duct or the intestines make bowel movements difficult, leading to extreme cases of constipation.
    • Vomiting: Intestinal parasites blocking the passage of waste to bowels induce vomiting
    • Diarrhea: Many of the protozoa type intestinal parasites produce a prostaglandin that causes sodium and chloride loss in the body. This leads to bile acid and fat mal-absorption, causing diarrhea
    • Parasitic infection might also cause loose and foul smelling stools or stools with mucus without necessarily developing into diarrhea.
    • Gas and Bloating: Intestinal parasites that live in the upper small intestines causes inflammation that leads to gas, bloating, and burning sensation in stomach, especially after consumption of hard to digest foods such as beans and non-organic meats.
    • Distended abdomen is a probable long term effect of such symptoms

  • slide 3 of 7

    Symptoms of Intestinal Parasites Related to Skin

    The presence of intestinal parasites at times manifest as allergies, tumors and various other skin conditions.

    • intestinal parasites cause the human body to release hormones and immune system defenders, which in turn irritate the skin and cause various skin conditions such as acne, hives, rashes, itching, weeping eczema, ulcers, swelling, sores, lesions, blisters on lips, and dermatitis. It also deprives the skin of its usual glow
    • intestinal parasites cause irritation and inflammation in the stomach, making it difficult to digest certain types of foods. The presence of undigested food particles in the stomach causes the body to produce increased levels of eosinophil, an immune system defender. These eosinophil inflame the body’s tissue and cause skin rashes.
    • intestinal parasites trigger the body’s immune system to develop a tumor-like mass known as granuloma to encase parasitic larvae or eggs. Granulomas usually develop in the colon, rectal wall, lungs, liver, peritoneum, and the uterus.
    • some intestinal parasites try to migrate out of the anus at night causing itching, discomfort, and irritation.
  • slide 4 of 7

    Symptoms of Intestinal Parasites Related to Chronic Fatigue, Pain and Illness

    Parasites cause chronic fatigue and pains in many ways.

    • the release of harmful toxic substances by the parasites, and the body working overtime to counter the ill effects of such harmful substances exhaust and deplete the body on physical, mental, and emotional levels.

    • intestinal parasites leech protein, carbohydrates, fats, and vitamins, draining the body of both nutrients and energy and weakening the immune system

    • some intestinal parasites move through the body and cyst themselves in joint fluids or muscles, causing pain, aching and irritation. Many people mistake such joint paints for arthritis.

    • the release of toxic substances by intestinal parasites and the counter-action by the body’s immunity system, or a weakened immunity system can lead to pain in the stomach or navel area, back, thighs or shoulder region.

    The chronic fatigue and pain manifests as flu-like symptoms, exhaustion, apathy, depression, listlessness, difficulty in concentration, forgetfulness, and impaired cognitive ability. People affected by intestinal parasites also suffer from extreme fatigue after very little physical activity.

    The presence of parasites makes the body produce immunoglobulin A, a defender against foreign substances. Over time, the body’s stock of immunoglobulin A gets exhausted, leaving the body susceptible to attacks from bacteria, yeast, fungus, virus, and other foreign invaders, causing a variety of illness such as fever, cough, colds, running noses, chronic sinus, ear infections, and the like.

  • slide 5 of 7

    Other Symptoms of Intestinal Parasites

    Some other less conclusive symptoms of intestinal parasites include the following:

    • Intestinal parasites secrete into the stomach, and a build up of such secretions over time can cause lack of appetite due to lack of space in the stomach to hold more food, and inability to lose weight. Conversely, the intestinal parasites feeding away on vital nutrients can also lead to a condition of always feeling hungry and rapidly varying blood sugar levels.

    • The presence of intestinal parasites very often manifest as recurrent yeast infections and frequent headaches.

    • Intestinal parasites that lodge themselves in the urinary tract cause urinary tract infections and problems in water retention.

    • Intestinal parasites that attach to the lining of the intestinal wall divert nutrients away from the human body. In severe cases of parasitic infections, this leads to reduced blood production and cause anemia.
  • slide 6 of 7

    Follow up on the symptoms of intestinal parasites with your doctor or other health practitioner to obtain treatment. The treatment usually entails destruction of the worms, and the body usually recovers itself once the parasites destruct or go away.


    The contents of this article do not constitute medical advice. Please read this disclaimer regarding the information in contained in this article.

  • slide 7 of 7


    1. University of Maryland Educational Center. Intestinal parasites.
    2. Parasite Cleanse Resource Center. 14 Common Symptoms of Parasites.