cannynancy,
They serve different purposes.
Slippery elm powder coates the whole alimentary canal.
While flaring, I used to take it 3 x per day, after each meal.
This is the way I would take it: 1 1/2 teaspoons of slippery elm in 1-2 oz. of room temp filtered water, add VSL#3 probiotics sachets into it, and a little honey (if you want), mix it well, smooth out the bumps with the back of the spoon, and drink it down. If it gets too thick, you can just add more water to liquify it more. It really works great together. Now in remission, I still take this but only 1 x per day, after dinner.
L-Glutamine powder is taken for 2 different reasons:
1) If you have D, you need to take it on an empty stomach, 1 teaspoon in a little water or juice on an EMPTY stomach.
2) For long term colonic/intestinal repair: take 5-10grams of L-Glutamine powder in a smoothie or protein shake.
Hope this helps.