If it's food poisoning caused by bacteria or their toxins, then nausea, abdominal pain and vomiting can begin as soon as an hour after one consumes the offending food. Bacteria can breed rapidly in raw or undercooked eggs, shrimp, shellfish, meat, sauces, fruits and vegetables and their juices. Buffets in which food is left at room temperature for several hours or where there is cross-contamination, such as a bit of cheese touching the meat, provide ideal breeding grounds.
On the other hand, symptoms of headache, general weakness, abdominal pains, vomiting and diarrhea could take as long as 48 hours to develop. It depends on the strain of bacteria and individual conditions.
Since a case of stomach flu could also take between 4 and 48 hours to develop, with very similar symptoms, the true culprit isn't always easy to identify. The stomach flu is caused by viruses that afflict the stomach and intestines, hence its technical name, viral gastroenteritis. These viruses are spread by the fecal-oral route and can persist on objects like doorknobs or on food surfaces for days.
Unless your doctor orders a lab culture, guessing whether your malady is bacterial or viral may depend on circumstantial evidence. Did a lot of people get sick at the same time after eating a suspect food? That suggests food poisoning. But if the illness passes in sequence between persons who have been in proximity, while others are immune, then a flu virus is probably responsible.
Is It Serious?
Most cases of bacterial or viral gastroenteritis resolve within a couple of days. As miserable as vomiting and diarrhea can make a person feel, it isn't usually serious unless symptoms are severe or prolonged, and dehydration, exhaustion or loss of electrolytes becomes dangerous.
Pregnant women, the elderly, small children and those with weakened immune systems are most at risk for developing serious complications. Gastroenteritis means that the stomach and intestines are infected and irritated. If it presents along with a high fever, bloody vomit or diarrhea, hardness and swelling of the abdomen, a rash, chills, joint pains or dizziness, then seek medical attention.
Other danger signs to watch for in children include projectile vomiting, vomiting for more than 8 hours or vomiting accompanied by high fever or increasing abdominal pain, warns Randall Neustaedter, author of the Child Health Guide, published in 2005. Dehydration can quickly become dangerous in small children, so watch for warning signs such as sunken eyes.
What to Do About the Symptoms
Avoid dehydration by drinking fluids like broth, weak tea, soda diluted with water or drinks containing electrolytes. Electrolytes such as sodium, potassium, magnesium, chloride and calcium are present in safe and balanced quantities in many sports drinks and especially in oral rehydration solutions. Stay away from caffeine and alcohol, which increase fluid loss. Painkillers are not recommended, as they may mask serious symptoms or cause further irritation in the bowels.
Rest as much as possible in between trips to the washroom. While on that topic, washing your hands vigorously with soap for at least 20 seconds will reduce chances of sharing germs with others. Those with the viral form can remain infectious for a week or two.
Once the worst is over and recovery begins, try eating bland and easy to digest foods such as oatmeal, crackers, apples, bananas and soup. Small quantities of red wine and probiotics such as fermented foods with live, beneficial bacteria will help restore intestinal balance and speed recovery.
Consult a doctor if symptoms become serious or persist more than 2 days.
