This information came from my very knowledgeable and helpful G.P
He said, if you catch threadworms you NEVER get rid of them... all you can do is bring the population down through good hygiene habits such as the ones discussed on this forum and numerous websites; wear tight underwear at bedtime, wash 'down there' every morning, wash hands and nails after doing this and wash hands and nails before preparing and eating food. If you have them, you are not alone, apparently 50% of the UK population has them.
He believes that killing them is a bad idea (whether that's using natural herbs or medication). When you kill them, the females will die inside you, decompose and leave the eggs behind. With around 15,000 eggs per batch in a female - that's alot of eggs you're risking being left in your body. He told me that even if you 'up' the dose of Mebendazole for example, it will still not kill every single female.
The best treatment is to paralyze them and then expel them - there are some suitable herbal treatments that can be used to both paralyze them and expel them - as well as Piperazine Phosphate which can be bought over the counter.
Do NOT use enemas or put anything round your bottom to deter them (garlic/teatree oil/vaseline etc). If they are coming down to lay their eggs at night, you want them to lay the eggs on the OUTSIDE of your bottom, not the inside where they will hatch and migrate back up to your Small Intestine to breed again. At least on the outside, you can wash them away again in the morning.
When the eggs hatch in the bowel and then migrate back up to the Small Intestine this is called 'retro-infection'. Killing gravid females in the bowel, makes retro-infection much more likely as does forcing them to lay their load inside you. To some extent the females will lay inside the body anyway, leading to retro-infection... and it's this that makes them impossible to get rid of.
Urban Myths:
1.) That you need to clean your house every day for 2 weeks - this is simply not true, unless in a cool damp environment the eggs become infertile after 1-2 days.
2.) You have to freeze bedding or boil wash it - this is not true either; the mere movement of the washing machine will disseminate any active eggs. A general launder is all that's necessary. Eggs have been known to survive temperatures of -8 degrees so freezing will prove redundant and is completely unnecessary anyway.
3.) Threadworms become resistant to the Mebendazole - there is no evidence of this at all - the problem is that Mebendazole does you no favours by killing the females whilst they're in your body, thus leaving your bowels full of eggs. This can cause them to come back 'with vengeance' (often even if you do take a follow-up treatment).
4.) That enemas help or garlic/teatree/vaseline around the entry to the anus helps. - this may be a short term solution but you cannot stop a gravid (egg laden) female from laying her eggs. If you deter them from laying outside your bottom, they will lay the eggs inside your bottom where you can't wash them away. If they're coming down to lay their eggs you WANT them to lay the eggs outside so that you can wash them away in the morning.
5.) They are most active at night when you are in bed and warm - Not true. They are most active at night (either moving around, laying or hatching) not due to your inactivity or warmth - people working on nightshifts are as likely to get symptoms then as people tucked up in bed. It's thought they have some internal navigation for predicting nocturnal time.
Unpleasant Truths
1.) Once you have them, you have them for life, although you may not get any symptoms because the population numbers are so low - once you have them though, the aim is to keep population numbers low.
2.) That they can 'migrate' to the lungs, nasal passages and sinus cavities through inhalation. You can get them in eyes and ears and they can also be transferred in girls to the vagina and urethra. Unfortunately if this is the case, Piperazine Phosphate will only paralyze them, but not expel them; when the PP wears off, the worm will be active again. Mebendazole will kill them but this can be counter-productive in the bowel, as it is prone to retro-infection.
3.) Symptoms include an itchy bottom (because the females produce an irritant when laying their eggs) this irritant can feel like shooting pains in other parts of the body (the ones mentioned above). Other symptoms can include appetite loss, nausea, bloatedness, aerated stools - with the consistency of a kind of dessert mouse, and excretion of a thin see-through liquid (produced as the eggs are hatching just on the inside of your bottom) - often you can see very small moving white dots - these are very very freshly hatched eggs. Sometimes the female adults can be seen at night coming down to lay their eggs around the anus (this is usually the main symptom prior to treatment).
4.) If you take one Mebendazole tablet then you MUST follow up with a repeat treatment or else you are going to be completely infested. The best treatment is not to use Mebendazole at all (or anything else that might kill the females inside you) and use Piperazine Phosphate (or some other herb that paralyzes and expels them) instead.
5.) A side effect of using Piperazine Phosphate or similar-acting herbs is that laxatives can cause you to strain which can lead to hemorrhoids. If you get these you shouldn't use a hemorrhoid cream (such as Anusol etc) as this will act to deter the females from laying outside the body thus again creating retro-infection.
6.) Threadworm breeding is at its highest in the Winter months October- February. If you have an outbreak - this is the most likely time.