My mom has this with some really awful flare-ups with many courses of heavy antibiotics. What helped her was this supplement:
TERRA ORIGIN Healthy Gut
(The Berry flavor is the only palatable one)
It has a lot of ingredients, if you can't take it because of any, the important things you could find separately.
Those include mucilaginous plants like Marshmallow, Slippery Elm, Licorice Root, and Aloe.
MSM is a source of sulfur, a great anti-inflammatory that is very natural.
And Glutamine is an amino acid found to help cell repair in the gut.
I first had her try this supplement because I'd given something with similar ingredients to my horse with ulcers (SmartGut). It really helped support his recovery, I could tell what a difference it made when I tried to take him off it then put him back on.
After a year of taking the Terra one, mom was able to stop using it and resume her normal diet. Which she didn't think she would ever be able to do again after the first flare ups and antibiotic rounds.