I think any time our bodies go through a trauma of surgery it goes into a reaction mode of keeping and then letting go. For example, after I had my babies, I did not lose my "normal" amount of hair for a long period of time (like my body was holding onto it), then about 4-5 mos. later...BAM It was a little disturbing to have a ton of hair keep pouring out day after day for a seemingly very long time. But eventually it got back to normal.
After a quick search I came across this article to somewhat back up my claim up there!
http://familydoctor.org/online/famdocen/home/men/general/081.html
Luckily my mom is an RN and was able to reassure me it was normal when it started happening after my 1st baby.
Another article w/ gastric bypass - I know it's different than the band but it's still weight loss surgery. This article also says that protein can help.
"Why do gastric bypass and hair loss seem to go hand in hand?
When many more hairs than usual are in the exogen phase at once, you notice lots more hair on your hairbrush. There are lots of things that can cause a disruption in your hair's cycle: hormonal changes (a dramatic change in diet can cause your hormones to think things are a bit difficult in the world, and they try to adapt), blood thinners (remember the heparin shots you got at the hospital right after surgery?), and the stress of undergoing surgery. Anesthesia is a possible risk factor as well. It is very common for people to notice more hair loss than usual about three months after having general anesthesia."
http://www.gastric-bypass-guru.com/hair-loss-after-surgery.html