What are erosion symptoms? Could it be diverticulitis? Weird symptoms one year after lap band!

The two most
common symptoms of erosion are either infection at the Lap Band port site, or
the feeling that the Lap Band is no longer effective. With erosion the
band is not inside the stomach rather than on the outside so it is effectively
no longer working. Vomitting and pain are not normal symptoms of
erosion. Vomitting is not a normal symptom of diverticulitis either so it
sounds like you may need some more investigations to determine exactly what the
problem is.

Your band has slipped again.  You should not be vomiting and having acid reflux with a deflated band.  If you are having these symptoms, your band moved out of place again.  consult with your bariatric surgeon.  You need to have an upper gi series and an EGD.  These tests will diagnose a slippage or a possible erosion.  You should consider having your band removed and revising it to the gastric sleeve or gastric bypass.  With the band it seems that once you have a problem, the problem never seems to go away.

You shouldn't be vomiting with a LapBAND unless there is something wrong with it.  Once a band has slipped, it is prone to slip again.  Get another upper GI x-ray to evaluate the position of your band.  If it has slipped again, you should probably have it removed, preferably with conversion to gastric bypass or sleeve gastrectomy at the same time.