this is hard question to answer if your sick with either and you dont know the difference then you havent learnt where your fullness point is, and knowing how much food is correct for the amount for the restriction you have at the time. everyone is different because of different amounts of fill and band sizes, once u learn when to stop eating portion wise and learn to listen to your body you can then learn from there, a block usually occurs if the food is eaten way too quickly and now chewed then the rest of the meal cant pass slowly and if u keep eating past the amount what your pouch can take it will make you vomit, this is where the importance of learning portion control must come into play with a band in my opinion. Also if your blocked you will start throthing up saliva when being sick as it has no pathway thro, ive tryed to answer this the best way i can.