I have had a guinea pig bounce back from that condition, but it took identifying and treating the underlying cause for it to happen.
In the particular case of mine my boy had a gastric upset from unknown causes, he had a sudden and drastic weight drop, abnormally shaped poops that were full of air pockets, poops strung together, and had stopped eating entirely. I began force feeding him critical care through a syringe (he wouldn't eat off a dish/spoon but would chew and swallow what I put in his mouth with the syringe). I called the vet and booked an appointment for the next day as it was about 5pm at this point and there are no emergency exotic vets in my area. Overnight he went into full GI stasis, as the food I was putting in wasn't coming back out I had to stop force feeding and get him into the vets urgently very first thing the next morning, luckily the motility drugs the vet was able to give him got his guts moving again so I was able to start force feeding again.
He started recovering but he took another week of full force feeding and another week after that of supplementary force feeding (as he started eating on his own again, but not enough) until he no longer needed supplementary feeding. I had to slowly add his vegetables back in to his diet one at a time to make sure he didn't relapse, and let me tell you he wasn't happy getting taken out every night at vegetable time when his cage mate got vegetables while he didn't, but he got through that without any issues and was back to normal and snatching his friends vegetables by the end of the fourth week.
I have also had a failure to recover from that kind of condition, however in this case I was expecting it to happen as I already had a diagnosis from a previous vet visit due to her losing weight. She had an inoperable mass in her abdomen and i was told her prospects were not good, but as she was still active and happy I took her home until her time came. It was about a month from diagnosis until the day she was in a condition similar to what you describe, low muscle tone, puffed up in the corner and off her food. It was that day I made the call to take her in and have her put to sleep.