So you've had diagnosis for the parasites(worms)then?
there are natural treatments for this which aren't as taxing on the body as they don't remove the good bacteria like antibiotics. assuming you have had correct diagnosis & it's not a condition like ceoliac disease or irritable bowel, one thing i use is olive leaf extract it is a bit slow but it can have many benefits for overall health. check my post in the cfs forum on helicobacter pylori as this is a issue that is very common in over 50% of the population & yet hardly gets treated or treated correctly.Also alkalizing your body makes for a less atractive environment for parasites in general & make sure you drink enough good filtered water.