Food poisoning will occur within 2-6 hours after eating contaminated food. Undercooked meats, dairy products, unwashed vegetables and food containing mayonnaise left unrefrigerated are all common vehicles for these infectious agents. Contaminated water supplies are also a main contraction point for food poisoning. "“Traveler’s (or Wilderness) Diarrhea” is a common condition that occur when someone drinks water contaminated with fecal matter. This is common in developing nations or places with an untreated water supply.

Episodes of food poisoning have been known to trigger a lifetime condition of IBS or IBD. In some very rare cases, food poisoning can also lead to death. Because of this possibility, it is very important to have a general idea of the dangers and symptoms of food poisoning.

Infectious agent: Virus

Noroviruses, Rotavirus and Hepatitis A are all viral forms of food poisoning that are transmitted through consuming water or vegetables that have been contaminated with feces. In addition, all three types of viruses can be transmitted from person to person. Noroviruses are the most common viral form of food poisoning in adults. It is called the “cruise ship illness” because outbreaks normally occur in very dense population like schools, nursing homes and cruise ships. The rotavirus shares all these characteristics but is mainly prevalent in children. Hepatitis A is only transferred through fecal-oral transmission and in rare cases, blood transfusions. In addition to the nausea, vomiting and diarrhea common in other viral food poisonings, hepatitis A will also cause jaundice, rashes and fatigue.

Infectious agent: Bacteria

Bacterial food poisonings affect the body by producing a toxin that is poisonous to the human digestive system. This usually leads to nausea and vomiting and possible kidney failure and death. The bacteria can also infect the intestines, causing inflammation and prompting diarrhea. All these bacteria cause the normal symptoms of nausea, vomiting and diarrhea, but they each have some defining characteristics.

The Salmonella bacteria will stay in the body and launch a secondary attack in the form of arthritis weeks after the initial infection.
Campylobacter is the most commonly identifies food borne bacteria.
Staphylococcus aureus is usually contracted pies, mixed salads and dairy products.
Bacillus cereus is usually found in starchy foods like rice or pasta.
The E coli bacteria will cause watery diarrhea that turns to bloody diarrhea and the worst strain can produce kidney failure.
Shigella is also referred to as travelers’ diarrhea. It causes diarrhea containing blood and/or mucus. Normally transmitted through contaminated drinking water.
Clostridium botulinum does not cause diarrhea but it attacks the nervous system and can be released into the air. For this reason it is considered and biological weapon.
Vibrio cholerae has the typical symptoms but only occurs in warmer seasons.

Infectious agent: Parasite

Parasites are the least common form of food poisoning, but they are contracted in the same ways as bacterial and viral food poisoning. The symptoms tend to be less intense than viral or bacterial food poisoning but last much longer. The Guardia parasite, also known as beaver fever, can cause watery diarrhea for two weeks. Cryptosporidium can make a person mildly ill with watery diarrhea for up to four days.