QuiltE - She probably had the lapband because it's less invasive hence cheaper. Mine was around $56K billed to Medicare but was actually paid around $30K.
If you google lapband surgery, it shows you that no cutting the stomach and making it tiny. The lapband simply puts a "band" around the upper portion of the stomach, creating that tiny pouch. The band itself is adjustable and can be adjusted by the surgeon as needed. From what I understand, the band can be tightened or loosened depending on how the patient is doing. The food goes into this tiny pouch created by the band then it slowly releases into the rest of the stomach for digesting. Since the stomach isn't surgerically touched, nothing changes for the patient other than the amount of food they can eat.
If the person is losing too fast (and getting sick), the band can be loosened a little to allow the person to eat a little more. My understanding is that the band CAN be removed......gastric bypass is a permanent surgery.
With the bypass surgery, since the stomach is surgerically altered, the "plumbing" of the digestive system is also affected which is why nutrients aren't absorbed like before. Again, google gastric bypass surgery and you'll find tons of videos and info on how this works.
One thing that isn't thought of -- I have bad sinuses so have a lot of sinus drainage which goes "into the stomach". So when I first had my surgery and this tiny little pouch (only holds 2 oz right after surgery), my sinus drainage filled my little pouch up and I couldn't eat (since I felt too full to eat). They had to go in via the throat and drain the mucous. Now, I have to take an allergy pill everyday too to keep the mucous down....again, something else doctors don't tell you. Now that my pouch has healed and can hold approx. 1-1/2 cups of food, the problem isn't as bad.
I do feel doing your homework for such a serious operation is necessary since gastric bypass is not reversible.