Small Guinea Pig poo?

You need to take your guinea pig to the vet. Well done for noticing the change in her poos. The vet might give her a shot of metocloprimide to stimulate her gut, and/or some probiotics to help her digestion. If she is not eating properly you must syringe feed her as guinea pigs can suffer from liver failure if they don't eat for 16 hours. You can syringe her the baby food (make sure it is vegetarian and NO ONIONS), and you can add some of the pellets from her dry food, crushed or dissolved, and maybe add some vitamin C as guinea pigs must have this as well. The gurgling tummy indicates she might have some problem in her gut. If she is not eating well she might have a problem with her teeth, so take her to the vet (one that knows about guinea pigs) for a check up.