My guinea pig is acting weird

Question
About two weeks ago I noticed my guinea pig was no longer using the corner of her cage to poop, but was pooping right in her igloo.  I then realized that in the last few weeks she has been spending most of her time in her igloo.  She doesn't popcorn anymore and seems really shy around us.  She seems to be eating fine, except she really only wants to come out to eat when no one is in the room.  Her stool seems normal, there is no discharge from her eyes or nose and her breathing seems fine.  The really weird thing is that when she's in her igloo she often sits on her butt with her front paws up.  She kind of looks like she's doing yoga. I've never seen her sit in that position before and it looks really strange.  I'm wondering if it's because some part of her body is hurting her.  We've had her since September and I believe she was just a few months old when we got her.  She had gotten pretty comfortable around us and seemed happy to see us when we would come in the room.  When I would open her cage door to give her hay or food, she would start squealing and popcorning.  She doesn't do that anymore and waits until we leave the room before she comes out to eat. Any ideas you have would be helpful.  Thanks.

Answer
Jackie,

It sounds like she maybe a little depressed and bored. Try spending a little extra time with her, handling her and talking to her. Also add a few toys to her cage and give her some extra floor time with some toys. That'll get her more active and with spending extra time with you she'll become more friendly again. Try also playing some classical music on a low volume near her cage. It sounds weird I know but the effect it has on Guinea Pigs is interest, it seems to calm them, relax them but also seems to make them more friendly.

If she is acting normal and allows you to pet her with out so much as a squeak in pain then nothing is hurting her. She maybe just a little jumpy and sitting like that to be more ready to run or something. If she keeps it up or your worried about it you can take her down to the vet and have her looked at to make sure there is nothing hurting her.

I hope this helps,
  Take care,
    Jules