guinea pigs being stopped up?

Question
My guinea pigs have some strange symptoms and I was wondering what this is.  They have slowed down on eating and drinking, and more than one has lost weight.  I thought they simply had a cold and didn't feel well enough to eat or drink when I saw that they have runny eyes and noses.  But they also started to have tarry stool and I don't know what to do. I'd appreciate any advice you can give me concerning this issue. Thanks so much

Answer
If you're asking are they constipated the answer is no, I don't think so.  Weight loss, loss of appetite and runny eyes are an indication of an infection, probably an upper respiratory infection. They need vet care and antibiotics. When a pig begins losing weight that's a serious red flag. Take them to see your vet asap.