Gastroenteritis
A self-limiting disorder, gastroenteritis (also called intestinal flu, traveler’s diarrhea, viral enteritis, food poisoning) is an inflammation of the stomach and small intestine. The bowel reacts to any of the varied causes of gastroenteritis with hypermotility, producing severe diarrhea and secondary depletion of intracellular fluid.
A major cause of morbidity and mortality in developing nations, gastroenteritis occurs in people of all ages. In the United States, this disorder ranks second to the common cold as a cause of lost work time and fifth as the cause of death among young children. It can also be life-threatening in elderly and debilitated patients.
Causes
Gastroenteritis has many possible causes, including:
bacteria, such as Staphylococcus aureus, Salmonella, Shigella, Clostridium botulinum, C. perfringens, and Escherichia coli
amoebae, especially Entamoeba histolytica
parasites, such as Ascaris, Enterobius, and Trichinella spiralis
viruses, such as adenoviruses, echoviruses, and coxsackieviruses
ingestion of toxins, such as poisonous plants or toadstools
drug reactions from antibiotics
food allergens.
Complications
In most patients, the disorder resolves with no sequelae. However, persistent or untreated gastroenteritis can cause severe dehydration and loss of crucial electrolytes, which can lead to shock, vascular collapse, renal failure and, rarely, death. Typically, infants, elderly patients, and debilitated patients are at greatest risk because of immature or impaired immune systems.
Assessment
The patient’s history commonly reveals the acute onset of diarrhea accompanied by abdominal pain and discomfort. He may complain of cramping, nausea, and vomiting. He may also report malaise, fatigue, anorexia, fever, abdominal distention, and rumbling in his lower abdomen. If diarrhea is severe, he may experience rectal burning, tenesmus, and bloody mucoid stools.
Investigate the patient’s history to determine the cause of his signs and symptoms, if possible. Ask about ingestion of contaminated food or water. The cause may be apparent if the patient reports that others who ingested the same food or water have similar signs and symptoms. Also, ask about the health of other family members and about his recent travels. (See Preventing traveler’s diarrhea.)
Inspection may reveal slight abdominal distention. On palpation, the patient’s skin turgor may be poor—a sign of dehydration. Auscultation may disclose hyperactive bowel sounds and, if the patient is dehydrated, orthostatic hypotension or generalized hypotension. Temperature may be normal or elevated.
Diagnostic tests
Laboratory studies identify the causative bacteria, parasites, or amoebae. These studies include Gram stain, stool culture (by direct rectal swab), or blood culture.
