I guess the first thing might be to determine what is causing the “gas attacks”? A gas attack does not necessarily lead to GI stasis and could even resolve without you giving medication- though I certainly would not hesitate to give my rabbit Simethicone if I suspected gas. I think it would best to try to determine what is causing her discomfort- if it is gas then you would look to diet modification to control the problem. What are you feeding? pellets? type? amount? what veggies?
I think it is great that you monitor her so closely and are on top of her input and output- but I would not stress out about GI stasis from what you are describing. It is always a possibility with rabbits- but I think you have her well monitored that you will be able to get her to the vet if she has something more serious than a gas attack. I am a little concerned that it is not known what is causing her discomfort- it could be something else entirely like bladder, etc.
I would suggest talking to your vet. But unless they are really, really rabbit savvy- you might get better diet modification advice here if that is what you decide as a first step- what to try to eliminate, how to do a trial, what has worked for others, etc. And if you can not get her “gas attacks” under control with diet then you could consider adding “probiotic” supplement to her diet. But if you do diet modification and probiotic at the same time- you will not know which one worked. A probiotic is a supplement and generally have little to no negative side affects- but I think it is important to prevent the problem as opposed to “treating” it if that is possible. Probiotics help support a healthy balance of gut bacteria and that in general leads to good GI health. If you are going to give a probiotic to your bunny I would make sure to get one formulated for pets and has no sugar and is dosed and palatable for bunnies. I know American Pet Diner makes a supplement or 2 with enzymes although I have not looked into them closely- and there are others that have been used in bunnies like Prozyme- but again, have not looked into it for bunnies.
I would not attribute the shedding to gas attacks. Shedding can cause an accumulation of hair in the stomach and GI tract when ingested during grooming- which has more to do with a hairball than gas. The fact that she is passing “pearl poos” in my opinion is a good thing- rabbits are so clean they are always going to ingest hair when grooming- and the best outcome is for it to pass.
I would at least call your vet and at the very least discuss this with them. But I would be curious to see what you feed daily, amounts, any treats, etc to see if you can figure out a simple solution.
My bunny Cotton hasa more delicate digestive system than my other 2 bunnies- I can give X amount of treats per day- but not all at once otherwise she can get a little mushy stool. But if I give the same amount divided by 2-3 times in the day- then no mushy stool at all. I think the craisins and natural sugar in the papaya tablets are too much if given at one time, but in small doses- no problem.