After antibiotic use establishes this, it can take on a life of its own, but correcting candida and bacterial flora imbalances can help, as the bacterial flora play a role in counteracting radiation.
The itching may be pinworms or other imbalances created by fungal candida and nervous system imbalances. It may also relate back to the inflammation of the CNS caused by past antibiotic use and exacerbated by about everything else. I would try Agrisept-L with that.
There may be some involvement of the vagus nerve as well. See how this improves.
The capsules do affect the entire digestive tract.