The character and severity of symptoms depend on the nature and dose of the irritant, duration of its action, resistance of the patient, and extent of involvement of the GI tract. Onset is sudden, with malaise, anorexia, nausea, vomiting, abdominal cramps, diarrhea, and prostration. If the diarrhea is intense, rectal burning and tenesmus develop. In severe cases, discharges may contain blood and mucus. If the fluid lost by vomiting has been excessive, alkalosis occurs; if diarrhea has been more prominent, acidosis is more likely. In the presence of severe dehydration and acid base imbalance, headache and symptoms of muscle and nervous irritability may be prominent. The abdomen is usually distended, with tenderness more common in the lower than in the upper quadrants. Bed rest with convenient access to bathroom, commode, or bedpan is desirable. Nothing is permitted by mouth so long as nausea and vomiting persist. When they cease, light fluids such as warm tea, barley or rice water, strained broth, cereal, gruel, or bouillon with added salt maybe taken. When warm liquids are tolerated, the diet may be increased gradually to include cooked bland cereals, gelatin, jellied consommé, simple puddings, soft-cooked eggs, and other bland foods. Salmonella Organism Almost all cases of food poisoning are due to Salmonella organisms. The incubation period varies from 6 to 48 hours, with an average of about 12 hours. Onset is abrupt, with headache, chills, fever, muscle aches, and prostration, accompanied by nausea, vomiting, abdominal cramps, and severe diarrhea. In sever cases, vomitus and rectal discharges may contain blood. Dehydration, acid-base imbalance, anuria, and shock may develop. The illness usually lasts 24 to 48 hours. It may be so mild as to permit the patent to continue his usual activities; rarely, it may fatal within 24 hours. Diagnosis is generally easy when the patient is one of a group that became ill after eating a certain food, and when the symptoms are typical. Gross examination of the food may disclose no evidence of contamination. Diagnosis is aided by demonstration of the bacteria in the food, vomitus, feces, blood, or urine. The organisms may persist in the stools for 7 to 10 days following infection. The treatment is essentially the same as mentioned in the second paragraph. Staphylococcus Enterotoxin Ingestion of a preformed enterotoxin produced by coagulase-positive staphylococci growing on a variety of foods (chiefly custards, cream-filled pastry, mil, processed meat, and fish), causes the disease. It is probably the most common type of food poisoning and is mainly spread by food handlers with staphylococcal skin infections. The incubation period is usually 2 to 4 hours after ingestion of food containing enterotoxin. Onset is abrupt, with nausea, vomiting, abdominal cramps, diarrhea, and occasionally headache and fever. The attack is short in duration, most often lasting only 3 to 6 hours with complete recovery. Fatalities are rare. The diagnosis is based on sudden onset after eating infected food, brevity of symptoms, and rapidity of recovery. Food poisoning can also occur after eating certain plants and animals containing naturally occurring poison. Mushroom poisoning symptoms begin within a few minutes to two hours after ingesting. They consist of salivation, sweating, vomiting, abdominal cramps, diarrhea, thirst, collapse, coma, and occasionally convulsions. Immature or sprouting potato poisoning symptoms occur within a few hours and consist of nausea, vomiting, abdominal cramps, diarrhea, and a sense of constriction in the throat. Practically all victims recover. Fish poisoning symptoms develop immediately or within 30 hours of ingestion and include numbness of the limbs, nausea, vomiting, diarrhea, abdominal pain, joint aches, chills, fever, sweating and painful urination. The severity of the attacks varies greatly and to some extent depends on the fish involved. Chemical poisoning can be caused by eating unwashed fruits and vegetables sprayed with arsenic, lead, or organic insecticides, acidic liquids served in lead-glazed pottery, or food stored in cadmium-lined containers. Severity depends on the amount of chemical ingested. The diagnosis is based on the clinical picture and history of ingestion of the offending agent. Bacterial food poisoning should be differentiated by careful tasting of the food. Absolute bed rest is mandatory. Little is to be gained by giving an emetic if there has been violent vomiting or diarrhea or if symptoms appear several hours after the food has been ingested. Otherwise, the bulk of the poison should be removed by gastric lavage.