Hi healing light, I am in the UK too! so we have the same challenges re Docs and also getting in the herbs that are freely availble in the USA.
I managed to get a referral to the Hospital of Tropical Medecines in London UCHL. I got the referal by being bloody minded and having my facts lined up. see my previous posts if you are interested.
Nothing showed up in stools. the only thing that can identify strongyloids is specific Antergen seriology tests.
Good luck with the Pin worm. if you look on Lorica Ladies pevious posts you have to be extremely clean for six weeks to shift them. Always make certain you and son wear pants in bed. Wash them every night. Flanels and towels wash daily and sheets as regularly as you can. it says to wash your rear thoroughly on rising then put the flanel in a hot wash afterwards etc......in other words....buy lots of cheap flanels...
it goes without saying about making sure you and your son wash hands every visit to the loo with hot water and soap.