Welcome to the site, although I am sorry that you have to be here and sorry as well to hear what your husband is going through with all of this. I too am from the UK, up here in Dundee Scotland. Here is a link from Macmillan regarding constipation that I hope will be of use and interest to your husband.
http://www.macmillan.org.uk/information … ation.html
As to this and everything else and also the nausea, I would definitely mention that to Prof Valle when you both meet with him next week as there are a wide range of meds that can be tried and also combinations of meds that you can try to help with the nausea. My dad suffered greatly with nausea when he had his CC and tried a load of them.
I am glad that your husband is under the care of Prof Valle's team and that he is meeting with him next week. Your husband is in very very good hands. Please let us know how things go and my fingers are crossed for you both.
My best wishes to you,