Chronic gut upset.
Colitis can be helped with herbs, but you have to change your diet, too.
People with bad gut troubles, severe colitis, Crohn's and the like, can, if they so like, stop the problem for a while, just by drinking a tea (decoction) made with strong astringents like alder cones or tormentil root.
Of course, the real solution to all and any chronic gut upset is to find the irritating food and stop eating that. If you have chronic gut upset a herbalist might give you alder cones to tide you over until you've pinpointed the source of your problems: the food that you're so allergic to that it perforates your gut. The food that you just can't stop eating, nevermind how bad it makes you feel. The food that you eat often enough that you don't notice just how bad it is for you.
Other herbs play a role in chronic gut upset. As a northern European herbalist I use herbs like Epilobium leaf, Filipendula flowers, mallows, and calendula. I expect north American herbalists to use slippery elm - it's one of their herbs.
But until you do stop eating the thing you're so severely sensitive to, no herbs will help you. Good herbalists will tell you so, too, and just might throw you out if you insist on wanting magic pills.
The astringents and other herbs are band-aids. They'll help you short-term, but, to use a turn of phrase I picked up on the herblist (thanks Jim!), sure, herbs will help you if your feet hurt, but you might also consider stepping out of the sizzling hot frying pan.