Hi, Thanks for your query, albeit short and specific. I noted the history of starting the problem 10 days ago with a backache followed by vomiting due to stomach bug as per your thoughts, passed out in bathroom once, now no vomiting or back pain but there is no energy and no appetite, and want to know how long does it take for stomach bug to bounce back from the said condition. Your history is suggestive of a disease that you had more than stomach bug as the there is vomiting, so much that you had fainted down in bathroom wherein the problems transformed into no appetite to no energy. I would advise you the following: Get the blood tests particularly for Widal that is for typhoid, blood culture to see whether the bacterial infection is still lingering. It is possibly be more than the viral infection of the stomach, that is intestines. Since you are still not sure, the best ways is to get the antibiotic cover which controls the bacterial infection and improves appetite and energy. Once the diagnosis is done the treatment becomes easy and guided. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. T Chandrakant