Have you discussed your symptoms with your Doctor.
Did you lose much blood during the operation? If so did the team take steps to reverse your anemia? Are they monitoring your anemia and working to increase your Red Blood Cells?
Have you confirmed that your listlessness it due to anemia? Perhaps you have an infection. Please contact your Physician immediately to discuss your symptoms.
Jan
Just a note on gastric bypass.
Gastric Bypass surgery carries two levels of risk. First, it is major surgery (although there is a new less invasive procedure available) that carries the following risks as published by the About website - "wound infection, hernia, ulcers, blood clots in lungs, and death". Second, it only works if the patient is very motivated and willing to follow the life plan prescribed by their Doctor...the following is also from 'About' - "To keep the weight off, those lifestyle changes your doctor prescribes will need to be permanent. Al Roker, for example, has given up his favorite McDonald's meals and exercises regularly. Carnie Wilson, who formerly binged as a comfort-eater, dines on healthy fare like grilled salmon and also exercises religiously. Carnie has commented that it's a one-two punch: when she exercises she doesn't want to undo the good she's done by downing a candy bar. Gastric bypass works, but you have to work at it!"
Nutrients such as iron are absorbed by the body via the intestines. By changing this intestinal route nutritions intake is changed. Your Doctor has no doubt put you on a regimine of suppliments.
http://weightloss.about.com/cs/gastr.../blgastby1.htm