Mango,
Welcome to the forum.
Curious, where did you hear about LDN to begin with?
Most doctors won't prescribe it.
I believe the reason your husband is getting such quick results with the LDN is because he is on the SCD diet.
LDN works most effectively with those on gluten and dairy free diets ( such as SCD or Paleo).
As far as constipation, my recommendation would be to try: some vitamin c, such as Emergen-C ( It's pretty gentle and well tolerated) or another natural for the body is Magnesium as in Natural Calm product.
Be careful with fiber because some types cause bacterial growth ( which you do not want). If you want to go the fiber route, I would suggest Acacia fiber as it doesn't allow for bacterial growth.
There are many other things you can do as well: l-glutamine powder, slippery elm powder, and if you are interested in any of this, there are things IMO that you can control, which will have a direct impact on
your disease, the symptoms you experience and their severity.
I was able to control my UC into remission through various
supplements, probiotics, diet modification, and LDN , low dose
naltrexone.
For more info on the protocol which has put me into remission,
please go to this link: https://www.healingwell.com/community/default.aspx?f=38&m=1666318 , and look at the 11th post.
I hope your husband feels better and let us know how we can help
you.