I think the best case for alternatives (especially traditional/native medicines) is that the root of most modern pharmacology is these very same sources - leaves, roots, barks, fungi .. etc. For example 5-asa (mesalamines) originates with Willow tree bark. While this neither increases or decreases the chances that Slippery Elm tree bark will treat either the symptoms or the underlying cause of UC, it does place things into perspective, and allows one to see that this "alternative" and big pharma's "5-asa" have some things in common. There would always be some possibility that a particular alternative source might the basis of the next wonder drug - not a high chance, but some chance. It is also possible that someone alergic to 5-asa (chemicaly related to Willow) might not be alergic to a similar substance derrived form Elm - and that woudl be good news for someone alergic to 5-asa.
Perhaps the next best case for SOME alternatives (the traditional medicine ones) is that the long use by healers provides some evidence that it is helpful in some way - or it would have been dropped. This is not a foolproof line of reasoning because there was also long use of leaches, bleeding, and consumption of exotic animal parts (like rino horn or monkey penis). Sometimes popular use is based on the most simplistic of thinking, and needs to be critically examined. But still, reading that something has been used for centuries by traditional healers, does lead me to give something a closer look.
I think other pro-alternative factors might include the fact that the expense is often (not always) less than new name-brand drugs (some generics are pretty cheap); and possibly just the psychological benefits of autonomy and control that one might feel studying up on something and trying it out. Passively waiting for some mysterious drug to work can be very frustrating - especially if it does not work so well/quickly for you.
Some of my caution towards alternatives relates to the thinner, or less organized, or less vetted research base, and/or the general lack of sourcing and manufacturing controls relating to impurities or potency. I am not a trusting sort, and the scenario that some quack might place some "stuff" in a bottle and try to get my money is a scenario that history tells us is VERY VERY plausible.
One of the biggest cautions against some alternatives, in my opinion, is the unfounded or downright silly things people often claim about them.
A preparation of slppery elm powder is a brownish-gray thickened goo not unlike sputum, which is not that surprising since it contains mucilage. stereofidelic89 says of this goo that "you can tell (just by looking at) will indeed repair your gut". Amazing. An ability of visual perception that I seem to lack. Should I consume all brown slippery goos? Perhaps the next time my cat vomits up some brownish mucus-ridden goo, I should lap it up?
While not as egregious as stereofidelic89's claims, many slippery elm websites use general imprecise terms like "coats" or "soothes" or make analogy to "salve on a wound" without really addressing how this fits with what we know about UC.
In the probiotic literature, we read that one way probiotics are thought to help is by boosting the integrity of the mucosal lining, which tends to leak with UC, and allows toxins to escape from the colon into our systems. To the extent that slippery elm does "coat", then it may be working in the same way - plugging micro-leaks. Spared the release of toxins, we might feel a lot better, possibly quickly. This line of reason is very attractive and has my attention.
There is also a general literature about the beneficial effect of antioxidents. In addition to 5-asa's more targeted action on IL-6 and IL-23, and Th17, it has an antioxidant effect. Whenever there is cellular damage, as with the mangled misshapen glial cells characteristic of UC, it seems reasonable that antioxidants, scavenging harmful free radicals would be a beneficial thing. Like its cousin the Willow tree bark, the Slippery Elm bark has lots of antioxidants. This is a 2nd line of attractive reason supporting use of Slippery Elm powder. (However this is not evidence that Slippery Elm power has any of the more direct effects on the immune system that derivatives of Willow Bark have.)
On the other hand, words like "soothes" without any discussion of the HOW of soothing, or analogies to a salve, or mention of Slippery Elms's promotion of mucous secretion, each raise some concerns for me.
Soothing is the reduction or mitigation of inflammation. But we have recently discussed how antihistamines and steroids differ in their anti-inflammatory effect. Something might prevent the initiation of the inflammatory process, something else might dampen the inflammatory response, and yet something else might mitigate the effects of inflammation. Whatever 5-asa does to inflammation, it is not the same mechanism as steroids. All anti-inflammatory effects good, but each very different. How does Slippery Elm soothe? It would be nice to hear some discussion along those lines to bolster the general claim that it soothes.
The whole idea of a "slave" is a protective coating allowing a healthy immune system and a healthy pattern of cellular reproduction to work from underneath to fix a wound. But with UC there is an unhealthy immune system, and the cells of the mucosal lining are not reproducing healthy copies. So does the salve idea even hold any water?
Personally, I am concerned about the large amounts of blood and mucus that comes out of my rear. Why would I want to take something that stimulates mucus production? I am not saying I won't ever, but I would like some discussion about why the existing overproduction of mucus is not enough. I am overproducing mucus in part because my mucosal lining is ulcerated - so how exactly is stimulating more mucus production going to protect me from ulcers, as some websites assert?
Finally, the traditional application of Slippery Elm has been on digestive issues such as gastric juices, motility, gas, bloating, stomach ulcers, malabsorption ... etc. BUT UC IS NOT A DIGESTIVE DISEASE, BUT RATHER AN AUTOIMMUNE DISEASE. An autoimmune disease in the lower part of the digestive tract to be sure, and a disease that has secondary symptoms (e.g., diarrhea) that are the same symptoms of digestive diseases. But, why are we looking at traditional digestive remedies, when perhaps we should be looking at traditional immune system boosters?
I am not anti-alternative. I am a curious and open minded person who likes to look into the whys and hows of things. I am frustrated by the illogical, unsupported, or outright silly things that some alternative advocates seem to say. I guess we can try to think things through, and avoid overly broad and/or simplistic claims; or we can start lapping up cat vomit.