I did it for 5 days after a severe IBS bout and it helped me put things back on track, but I also followed the GAPs protocol of adding foods back in. Unfortunately I was traveling shortly thereafter so it was just to get me healed enough for the trip.
I plan on doing a full GAPS again after I get moved and settled so i can do it for the length of time I need for proper healing.
Its a good idea if you need to do it, you can do avocado and boiled carrots after a day or two to help feed yourself as well.
Toss a few whole chickens in a big pot and simmer away for hours (minimum 5-recommend 6-8) toss in a few carrots. They say just reboil the broth every 4 days and it will remain good, no need to toss anything.
I strain it for clarify it so its a golden consume (its more appealing to look at sometimes). You can add some plain gelatin if you need it as well, this helps for repairs, or if you didn't get enough goodness out of the carcass.
They say you can use a whole roasted carcass after you've eaten it and simmer that up, but I've not gotten good results for some reason. (I can only do chicken because of allergies)