If you get flu-like symptoms, such as vomiting and diarrhea, after eating chicken, it's likely that the chicken was undercooked and was infected with either salmonella or campylobacter. Salmonella and campylobacter are both bacteria that are among the most common causes of food poisoning, according to the Centers for Disease Control and Prevention. Though there are many other organisms that cause food poisoning, these are by far the most likely sources from eating chicken.
Most strains of salmonella that are toxic to humans produce gastrointestinal symptoms, according to the Mayo Clinic. Chief among these are vomiting and nausea. In addition to vomiting, you will also likely experience abdominal pain and cramping. A campylobacter infection may produce vomiting, but it is much less likely to occur than with salmonella.
Diarrhea is the most common symptom of campylobacter. According to the CDC, campylobacter is the most common bacterial cause of diarrhea in the world. Diarrhea is also a possible symptom of salmonella infection, and if you have a severe case of the illness, you may see blood in your stool.
Because they are bacterial infections, both salmonella and campylobacter can cause fever. The fever is usually mild, although the Merck Manual say a fever that accompanies campylobacter can be as high as 104 degrees Fahrenheit.
Both salmonella and campylobacter infections can produce general feelings of illness, such as muscle pain, chills, headache and fatigue. Both diseases can also cause serious complications, such as dehydration, blood infection and a kind of arthritis called reactive arthritis.