My mom is in the same situation...her gastric bypass was necessary to repair damages from previous operations and she now looks like skin and bones...any helpful reply would be appreciated if anyone know what the hell this is.

It is a reaction from the surgery. The gastic bypass is so dangerous and most people who get it have adverse reactions like not being able to eat and developing other disorders from it. My biggest suggestion is to convert to a high in nutrient liquid diet. If you can't get solids down, that is the only way to get back up to a healthy weight and get your vitamin levels back to normal.