Guinea pig has been constipated

Question
Hi, My guinea pig hasn't been eating, so I went through everything I could think. I thought she might be rebelling from lack of attention or not having hay to eat, but I went and bought expensive food and hay and am giving her treats. I cleaned out her cage 2 days ago and I noticed she hasn't poo'd. I'm scared it's been this way for a while and I'm worried its too late. Money is tight and a vet visit is a last resort. Is there anything I can do to help her?

Answer
You don't say if she has lost weight. Generally if they're not eating they begin to lose weight and is noticeable. One of the first things that comes to my mind is whether or not her water bottle spout is not working, making it impossible for her to get water. Without water she will not eat. She needs water to digest.

I would recommend you give her some lettuce and carrots to see if she is able to eat at all. If she will take the lettuce she will be getting hydration (water) from that. If she refuses to take the lettuce or carrots there may be a problem with her teeth.  

It's unusual for a sow to get constipated. Boars will sometimes have problems passing stool because of the pouch they have that will collect debris and make it difficult for them to go. Constipation is defined by having stool there, but it's either so hard or so dry they cannot pass it. If she's not been eating there isn't any stool being formed. That's a nutritional problem, not constipation.

Open her mouth and check the teeth. If she has a malocclusion (deformity) in the teeth that could explain why she is not eating.  She's not able to chew.  So check that first. The teeth are easy to trim. Their teeth are not like ours. They're more like fingernails. They grow constantly and occasionally are not properly worn down and need to be trimmed. A small pair of toenail clippers will do the job. Or you can take her to the vet and have it done. It's a simple and inexpensive procedure.

For the time being don't buy any other 'expensive' food. The price isn't always a guarantee that it's the best.  Give her fruits and veggies to see if that won't stimulate her appetite. But do check her water bottle to be sure it's working properly.  Sometimes the spout gets stuck and we don't know it unless we're really paying attention.