May I suggest for your husband to start juicing one bunch of celery every morning and drink it on an empty stomach. You can read more about the amazing benefits celery juice on this blog. I can't explain as good as the link.

My husband used to suffer every time when we travel (I really mean every time). After reading about celery juice, I started the regiment first and saw great improvement on the health problem I was experiencing. He joined in after two months. He is now the one telling other people to drink celery juice first thing in the morning. It's almost like a miracle in a way. It works in mysterious ways to help your body heal itself and improve the hydrocloric acid.

He used to get sick from eating a lot of different fruit and vegetables, but since he started on this celery juice journey (7 months now), he is able to enjoy all the food that he hasn't been able to enjoy for years!

You can find all kinds of people on Instagram swearing by the healing power of celery juice. I am one of them :)