Swollen knees on down to feet and just on Lialda

Hey all....I go bk. to the doctor on Friday but can't understand WHY above my knees all the way down to my feet are greatly swollen. All I am on is 4/Lialda a day, no steroids. I did read that this COULD be a possible side effect but not common. I was on this before and didn't have this problem. Weird! Have had blood tests done only showing I was slightly anemic and my organs (liver, kidneys,etc.) are just fine. I think it is the medicine. I have a desk job and prop my legs on a box as much as I can and on pillows at home. Gah! What gives? Luckily, I feel overall I am getting much better. Yay! I don't eat much if any of salt and only drink water right now. Hmmm?