koronakid,
what protocol are you following at the moment? - i.e. how much L-glutamine are you taking?
One thing you could try if you get constipated is to cut back the dosage. You want to take enough L-glutamine so that you can feel your gut healing, but not so much that it constipates you.
Its interesting that you say MSM also heals your leaky gut. I wonder if it is actually healing it, or just lessening the symptoms?