Brief Answer:
Recommendations for influenza and for gastroenteritis.

Detailed Answer:
I am sorry you are feeling ill.

Two things are referred to as "flu" and are entirely different from each other so I will write about both.

The real flu is short for influenza. This is a respiratory illness caused by an influenza virus. It can be mild or severe. There are common flu viruses that circulate every year and then there are more severe pandemic types such as H1N1. In the US, flu shots are recommended in the fall to try to prevent the common type of flu, but their effectiveness varies from year to year because the researches who make them are making their best guess predicting which flu viruses are going to be prevalent the next year. They don't always get it right.

Symptoms of flu: Usually flu starts so abruptly people can remember when it started. It can be like a severe cold with runny nose, sore throat. And a cough. There are usually body aches and pains, especially in the low back and upper backs of legs, and fever/chills.

If flu is caught in the early hours, antiviral medicines can help decrease the total length of the symptoms and the severity somewhat. But it can't cure it because it is caused by a virus.

Otherwise, there is no treatment medicine. Hot tea and soups, lots of fluids (water, juice), acetaminophen (paracetamol) or ibuprofen for fever and pain. Guaifenesin for clearing secretions. Sometimes a decongestant if there is a lot of nasal congestion - such as pseudo ephedrine or phenylephrine. If severe respiratory symptoms, go to a clinic for an Xray to make sure there is no pneumonia.
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Now about the other "flu" which is not flu but is gastroenteritis. This is usually caused by viruses, at least in the US, but in less developed countries without proper water sanitation, it can be from bacteria or protozoa as well. Symptoms can be nausea, vomiting, and diarrhea and abdominal cramps.

Treatment depends on the cause. For viral gastroenteritis, this usually lasts a limited length of time, and easy to digest foods such as teas, broths, rice, toast, bananas, and apple sauce may be tolerated well. Avoid spicy and greasy foods, nuts.

If the cause is something other than a virus that is "going around", treatment depends specifically on what the cause is.

If not able to tolerate liquids, then the patient may need bowel rest with an IV fluid to keep hydrated.

I hope this information helps. If you have more specific information that I can help with, please let me know how I can help.

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