Can your gall bladder cause you to be anemic?

My father has been having some pretty serious health issues lately. He was hospitalized with pneumonia and CHF a few weeks ago and then relapsed shortly after he was discharged from the hospital. Luckily they caught it before it got really bad again and the second time he was treated with oral antibiotics and Lasix at home. Then he began feeling very nauseated and tired and became very anemic. We thought it was his medication and the doc thought he was losing blood from his stomach/intestines. He actually had to go into the hospital over the weekend because he was so weak he couldn't even get up to eat or go to the bathroom. After running a lot of tests the only thing they could find wrong with him was his gall bladder, which they removed today. He says he feels a million times better which is wonderful but could that have caused him to become so weak and anemic? He's lost so much weight too, he's 5' 10" and only weighs 136 lbs. I'm just worried they're missing something.