@duckduck2020
Hi, my wife has had trouble at previous times of her life with constipation. She is no longer troubled with that since she started taking an Ayurvedic remedy called Triphala. I would recommend that your husband try this product. It is natural and can be very potent for getting things moving. Here is the Amazon link:
https://www.amazon.com/gp/product/B00DZ4T0XQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I realize your husband has a severe issue and it might seem like a heavy duty solution is called for, but this stuff is gentle and works on a subtle level that other things he may have tried do not. At least it may be different than other things he has tried. I hope it can help him. I am so sorry for his suffering. I know personally what it is like to not have a smooth running system, and it's not fun!

My heart goes out to you both for having to deal with chemo. My wife went through that for breast cancer, and the chemo was by far the worst aspect of the entire ordeal. She stopped the chemo halfway through and began using a product called Haelan951 that has kept her cancer free now for 5 1/2 years (after 5 previous bouts that came faster than once per year).

Wishing good luck for you both. My best to you, Hank