Ron, from what I understand, if you have a smaller stomach you would tend to be hungry more quickly. Less food will fit inside your stomach, therefore you may need to top up sooner than someone with a smaller stomach would. I know a couple people who have had their stomach reduced in size and this is the case for them.
The malabsorption would affect you basically because parts have been removed and almost all the parts are responsible for absorbing different things along the different stages of digestion. Depending on exactly which pieces are gone, (which is kind of hard to be exactly sure of, and also figuring what they may be responsible for) you may be missing important areas that would normally absorb a certain vitamin, nutrient, water or even bile.
The function of the ileum is mainly to absorb vitamin B12 and bile salts and whatever products of digestion were not absorbed by the jejunum (near the start of the small intestine). The wall of the ileum itself is made up of many folds, each of which has lots of tiny finger-like protrusions known as villi on its surface. The villi contain very large numbers of capillaries that take the amino acids and glucose produced by digestion to the hepatic portal vein and the liver(it's like the last chance for a lot of things to be absorbed properly once it passes this point). If things aren't fully going back into the hepatic portal vein and the liver, they will mostly just be excreted in your stool.
I took biology in college.
I happen to remember a lot still, but I had to refer to my old notes a little bit.