Blastocystis hominis is often found in patients with long standing, fungus type intestinal problems. Yeasts or other parasites like giardia lamblia even a former infection heighten its effects (West J Med, 1989; 151: 518-9), as will a so called "leaky gut".

B hominis can suppress your immune system and worsen food allergies or intolerance.

The herb Berberis vulgaris has been shown to be effective against B hominis (Indian J Exp Bio, 1976; 14: 345-7), though the treatment may need to carry on for up to six months.

Public water supplies and swimming pools are often the culprits of Cryptosporidium infections.

Both Berberis and Artemisia annua in combination offer an effective treatment (Tokai J Exp Clin Med, 1990; 15: 417-23), though you need to continue treatment for up to three months.

Traditionally, South Americans have cured themselves of the whipworm Trichuris trichiura with fresh fig sap, which decomposes the worm's proteins (M J Chatton, Handbook of Medical Treatment, Los Altos, CA: Lange Medical Publications, 1972: 531).

Threadworm, a Strongyloides species of worm, can be eliminated with an enema of Picraena quassiodes, known as quassia or picrasma.

Use 2 to 4 ml of freshly prepared infusion mixed in cold water in a ratio of 1:20 on three successive mornings (British Herbal Pharmacopoeia, Part 2, W Yorks: British Herbal Medicine Association, 1979: 137-9).

Carrots are particularly prized by naturopathic physicians for treating threadworm in children.

Give your child nothing but unlimited amounts of grated carrot for two days, with a daily mug of freshly made carrot juice at breakfast (R F Weiss, Herbal Medicine, Gothenburg: Ab Arcanum, 1988: 121).

Tapeworms can be successfully removed with Aspidium filixmas, the male fern.

To guarantee potency, go to a medical herbalist not only experienced enough to distinguish this fern from three lookalikes, but also willing to go into the woods to dig up fresh roots. Since large doses can be toxic, never take this remedy without expert supervision (J Chiropractic Acad Hom, 1996; 7: 49-54).

In Oriental Medicine, the Java brucea fruit (known in Chinese as ya dan zi and in Japanese as atanshi) has been shown in many studies since the 1950s to be effective against the malarial parasite, and many other parasites, with less than a 6 per cent recurrence rate (D Bensky, A Gamble, Chinese Herbal Medicine: Materia Medica, Seattle, WA: Eastland Press, 1993: 97-8).

Lapacho, found in Tabebuia avellanedae, or Pau d'Arco, can be applied on the skin or taken orally to prevent infection with the widespread, debilitating tropical disease schistosomiasis (Am J Trop Med Hygiene, 1974; 23: 412-9).

Insist on standardised lapacho content when purchasing Pau d'Arco medications or teas.

One analysis of 10 products on the market showed that nine contained no lapachol, and only one contained mere trace amounts of it.

Papaya is often used by naturopaths to treat ringworm, pityriasis versicolor and other parasitic worms.

First mash up green papaya in vinegar and apply this topically to the infection (if ringworm or pityriasis) once a day for three days. For intestinal worms, drink 60 ml of the vinegar for three days (E F Steinmetz, Codex Vegetabilis, Amsterdam: Steinmetz, 1957).

!AHarald Gaier

Harald Gaier is a registered osteopath, naturopath and homoeopath.