Both of these forms of herbal medicine have excellent properties, some unique to themselves and some they both share such as the ability to aid constipation and other forms of bowl distress which is what they’re most commonly used for that I’ve seen across social media platforms and recommended by many veterinary herbologists .
There’s one aspiring difference between the two, and that’s the ethics behind Slippery Elm as there isn’t many mature trees left in nature any more, herbologist and botanists believe it will be on the endangered species list soon , some believe it already is which is a great practice as it helps find alternatives!
Which is why I mention Marshmallow Root, which isn’t so much of an issue with resourcing ethically like Slippery Elm!
However there are many other ailments where you may have to alternate or combine the two to get the desired results , therefore please do your research before you buy slippery elm and make sure it’s been ethically sourced!
Now as I’m not a herbologist or trained in anyway in respect of Traditional Chinese Medicine or the likes of those that use herbs in a medical way, I will not tell you what they can and can’t be used for, you will have to research yourself. I simply wanted to highlight the downside of using the every so popular Slippery Elm but it’s purely due to the ethics behind the longevity of the species! 🙂
References for the relevance of both: https://www.ncbi.nlm.nih.gov/pubmed/19799989 (Marshmallow Root)
Edwards, Sarah & Rocha, Inês & Williamson, Elizabeth & Heinrich, Michael. (2015). Slippery Elm. 10.1002/9781118543436.ch102.