Seriously, what could cause stomach flu symptoms for over a week??

i really need to know..

Hepatitis can cause flu-like symptoms and nausea and lack of appetite along with other symptoms. There are different types of Hepatitis, and these types are spread in different ways. Here is a good website or two below.

THere may also be other illnesses linked to your symptoms. If it's been going on for a week, you should see your doctor.

Also, some severe food allergies can cause these types of symptoms, especially in people with celiac sprue disease, but since it came on quite suddenly (from what you indicate), it may not be related to this, but I just thought you might want to consider it.

Gastroenteritis (stomach flu, etc.) can be caused by many many different things. It can be caused from a reaction to medication (antibiotics, antacids, etc.), virus, parasite, microorganisms, some health conditions like ulcerative colitis or ingested chemical toxins and if you have a weakened immune system you can be particuarly at risk.
Infections can be transmitted person to person, usually when a person with diarrhea doesn't wash their hands enough or at all (GROSS!) and if you are in contact with them or if they have handled food or water you ingested (GROSSER!). Foods or beverages can be infected with bacteria and unpastuerized or not cooked well enough or not at all like raw shellfish. You can ingest water at a lake, pond, or swimming pool that has been contaminated from stool from an infected person or an animal, or being in contact with an infected animal.
Chemical toxins that can cause gastr. are poison mushrooms, some exotic seafoods, food or water with lead, arsenic, cadmium, or mercury, some people can even get it from a reaction to acidic foods like large amounts of oranges, grapefruit, or tomatoes.
Campylobacter, salmonella, shigella, different strains of E. coli, different strains of clostridium, entamoeba histolytica, different strains of vibrio, and staphylococcus aureus, giardia, cryptosporidium, and viral infections such as rotoviruses, Norwalk virus, astroviruses, and enteric adenoviruses are some of the microorganisms that can make you sick.
Most sicknesses only last a couple of days, but some can last up to 2 weeks, and of course the most important thing is to not get dehydrated or let your electrolytes get out of balance, both can be life threatening.
The only way to really know for sure is a stool sample, but that probably depends on how sick you are if they will do that. Good luck and feel better!

Actually the salmonella outbreak can cause flu-like symptoms. They can last a week or more. They just determined it may not be linked to the tomatoes and peppers instead therefore a lot more people are beginning to get sick. I would see a doctor, it has been going on too long.

H. pylory ( a bacteria) and some protozoa like entamoeba colli, giardia lamblia and blastocistis hominis. I suggest you to have a blood test and a feces test.

It actually COULD be the Stomach Flu; or food poisoning; or a gastro-intestinal virus... -your diagnosis is as good as mine... (But if you're not feeling better by Monday- go see a Doctor.).