I'm sorry to hear that your girl Ruby isn't herself with lots of stomach gurgling, lack of an appetite and lethargy.
The noises that you are hearing are the result of ingesta moving through the gastrointestinal tract and gas bubbles. In most cases they are completely normal and seem to cause the dog no distress. But in cases where the dog acts uncomfortable it is likely that the pup is experiencing some reflux or abnormal motility, or painful intestinal spasms that are more than the usual. In severe cases this can be linked to pancreatitis which is a painful inflammation of the pancreas leading to increased enzyme leakage.
Possible causes for this include a change in diet, dietary sensitivities or allergies, or eating things that she should not have like too many fatty table scraps or garbage, bones etc. Metabolic organ failures (kidney or liver disease), Addison's disease (hypoadrenocortisim), pancreatitis, inflammatory bowel disease or even infiltrative cancers are other possible causes.
Has she gotten anything different to eat or has she gotten into anything that you know of that may have started all of this?
I can give you some suggestions but ideally if she isn't coming along quickly over the next couple of days I would recommend checking basic blood tests on her including a complete blood count, biochemistry panel and a blood test for pancreatitis called can spec PL (canine specific pancreatic lipase) which is highly specific for pancreatitis.
If her electrolyte levels seem unbalanced (high potassium and low sodium) then testing for Addison's disease with a test called an ACTH response test would be reasonable.
If those things are normal then the next step diagnostically would be an abdominal ultrasound and endoscopy to collect intestinal biopsies.
But for now here are some suggestions.
For now to help with gastrointestinal upset and reflux you can give either:
1) Pepcid ac (famotidine) at a dose of one quarter of a 10mg tablet every 12 hours
2) Prilosec (omeprazole) at a dose of one quarter of a 10mg tablet every 24 hours
These are acid reducers and should help her feel more comfortable. They are quite safe and can be used for a few days if needed. In some cases dogs remain on them long term if this is a repeated problem.
I would pick up all food for now and water for a couple hours to allow her stomach to settle after the acid reducers. In a couple hours you give her water or low salt clear broths like low salt beef or chicken broth to drink, but make sure it is in small amounts only.
If she seems to feel better by tonight offer a bland diet mix of 1/3 boiled, minced, white, skinless chicken or boiled, lean hamburger, all fats drained off the meat after cooking, and 2/3 boiled, plain, white rice, mashed potatoes or pasta mixed with some low salt chicken or beef broth to make it easy to lap up and swallow as well as increase her fluid intake. If she refuses that you can offer a little meat baby food. If she refuses both then don't push it she likely needs to be seen by your family veterinarian.
Probiotics such as Fortiflora, Proviable, or Benebac can be added to the bland diet mix to help replace appropriate bacteria.
If things go well and she eats and seems more comfortable feed her the bland diet for 2 to 3 days then slowly start to mix back in her regular food, a little more at each meal. It should take about 5 to 7 days to slowly convert her back to her regular diet.
If she continues to be lethargic, begins to vomit, runs a fever (more than 103F rectally), or has a tense painful belly then she is not a candidate for home therapy and must see a veterinarian for an examination, diagnostics, injectable anti-nausea drugs intravenous fluids and supportive care.
If you go back to her original food and stop table food and treats and her lethargy and gastrointestinal noises return then you may wish to consider using a using a low irritant food, like Hills or Royal Canin Sensitive stomach formulas. If those aren't enough then she may need Hills i/d or Purina Veterinary Diets EN, or Royal Canin Gastrointestinal formula.
Please let me know if you have any further questions.