Spinach is a great source for magnesium and calcium among other things. Perhaps that's why it is so helpful in treating flares.
When I went camping in the mountains, my poo got a lot more formed and I was going less. My stress level was the same if not more due to the experience of camping in the mountains for the first time with other people.
Anyway, the only difference I could find was that I was drinking hard water, which contains a lot of magnesium and calcium. Some people could not drink this water. They were getting headaches and swelling. But for me, I think the water really helped improve the condition of my poo.
I'm now taking magnesium and calcium supplements in addition to eating spinach and sunflower seed nut butter. It's making a difference. My poo is much more formed and I'm going less often.
Colitis is in remission. No longer get IBS.
Figuring out how to reduce a flare or get into remission is a trial and error experience. Don't expect your GI to have all the answers. He was trained in making diagnoses, prescribing medications, and surgically removing the colon. He was not trained in alternative treatments. That's why they are called alternative treatments.
What works for me: Fecal transplantation, Probiotics, Anti-inflammatory foods, No HFCS, No crystalline fructose, No foods high in fructose, No artificial sweeteners, No pro-inflammatory foods when flaring, vitamins & supplements, Lexapro (for stress).