Thank you for your question that has just come through to me.
I am very concerned about your girl. What your are describing with your dog sounds like gastril dilatation and vulvulus (GDV) or twisted stomach.
This condition is life-threathening and more common in deep chested dogs, especially following a large meal. In the bloated stomach, gas and/or food stretches the stomach many times its normal size, causing tremendous abdominal pain, this is most likely why your girl is pacing and seems uncomfortable.
If she has got GDV then it is imperative that you get her seen by a Vet as soon as possible as she could die without emergency treatment.
There are several clues that a dog may have GDV: an obviously distended stomach, especially near the ribs, but this is not always evident depending on the dog's body configuration.
The biggest clue is the vomiting: she will appear highly nauseated and retch but little food wil be coming up. It may be that your girl hasn't reached this stage yet.
If this is seen, rush your dog to the veterinarian IMMEDIATELY.
There are several steps to saving a bloated dogs life:
The Stomach must be decompressed - the huge stomach is by now pressing on the major blood vessels carrying blood back to the heart. This stops normal circulation and sends the dog into shock.
There can be no recovery until the stomach is untwisted and the gas is released. A stomach tube and stomach pump are generally used for this but sometimes surgery is needed to achieve stomach decompression.
Rapid Intravenous (IV) Fluids must be Given to Reverse the Shock - intravenous fluid solutions are given at at rapid rate to replace the blood that cannot get past the bloated stomach to return to the heart. The intense pain associated with this disease causes the heart rate to race at such a high rate that heart failure will result.
Once she is stable, surgery is carried out to anchor her stomach in place and prevent recurrence of this problem in the future.
I hope this has been of help to you, please reply if you need further info. I hope your girl is feeling better soon.