AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Background

Gastroenteritis is a very common pediatric condition and is second only to respiratory infections as the most common reason for unscheduled visits to pediatricians.

Pathophysiology

Gastroenteritis is a clinical syndrome caused by a variety of viral, bacterial, and parasitic enteropathogens. The mechanisms potentially responsible for viral diarrhea include lysis of enterocytes, interference with the brush border function that leads to malabsorption of electrolytes, stimulation of cyclic adenosine monophosphate (cAMP), and carbohydrate malabsorption. The proposed pathophysiology of bacterial gastroenteritis involves the elaboration of toxin by enterotoxigenic pathogens and the invasion and inflammation of mucosa by invasive pathogens. Parasitic organisms invade epithelial cells and cause villus atrophy and eventual malabsorption.

Frequency

United States

Incidence rates for diarrhea are 1-2.5 episodes per child per year, which annually leads to approximately 38 million cases, 2-3.7 million physician visits, 320,000 hospitalizations, and 325-425 deaths.

International

More than 1 billion cases and at least 4 million deaths per year are attributed to diarrhea worldwide.

Mortality/Morbidity

Mortality and morbidity from diarrhea relate to the degree of dehydration. Most deaths in the United States correlate to lower maternal socioeconomic factors and prematurity.

Age

Dehydration risk in children relates to age, and infants are most susceptible.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

History

• Pertinent information includes the following:
• • Presence or absence of vomiting
  • Frequency, duration, and character of diarrhea
  • Travel history
  • Contacts with sick individuals
  • Antibiotic use
  • Seafood ingestion
  • Possible ingestion of toxic substances
  • Chronic illness
• Determine the amount and type of fluids ingested for the past 24 hours and the child's urine output.
• Seizures in a patient with diarrhea should raise the possibility of gastroenteritis caused by Shigella species, enterohemorrhagic Escherichia coli, or an electrolyte imbalance. Hyponatremia is more common than hypernatremia.
• • Consider hyponatremic dehydration in children who have been fed bland and dilute fluids (eg, tea, rice water, dilute formula).
  • Consider hypernatremic dehydration in patients who have been drinking mainly salt solutions and other hypertonic solutions, who have been losing hypotonic fluids (eg, profuse watery diarrhea), and who present with a depressed sensorium beyond what would be expected from the apparently mild signs of dehydration.

Physical

• The criterion standard and most accurate clinical indicator of the extent of dehydration is the percentage loss of body weight during the illness, which represents the child's fluid deficit.
• Other vital clinical findings
• • Thirst
  • Listlessness
  • Dry mucous membranes
  • Sunken fontanelles
  • Sunken eyes
  • Absence of tears
  • Decreased skin turgor
  • Decreased capillary filling time
  • Tachycardia
  • Weak pulse
  • Reduced blood pressure
• Examine the stools to check for mucus, blood streaks, or gross blood
• Tenting or loss of skin turgor (eg, when pinched skin does not return to the original flat shape) usually occurs in moderate-to-severe cases of dehydration yet is not always present in dehydration. Tenting or skin turgor loss seldom occurs with hypernatremic dehydration, a condition in which doughy skin is more common.

Causes

• Bacterial infections cause most gastroenteritis cases in less affluent nations.
• • The most important causal agent in these countries is diarrhea-causing E coli (eg, enteropathogenic [EPEC], enterotoxigenic [ETEC], enteroaggregative [EAEC], enteroinvasive [EIEC], enterohemorrhagic [EHEC]).
  • Other bacteria that cause gastroenteritis less often are Campylobacter, Aeromonas, Shigella, and Salmonella species.
  • Vibrios species, especially Vibrios cholerae, play major roles in epidemics. In seafood poisoning, Vibrio parahaemolyticus is associated with gastroenteritis.
• Viral infections cause 30-40% of gastroenteritis cases in affluent countries.
• • Rotavirus
    • Rotavirus accounts for about 3.5 million cases per year and as many as 110,000 hospital admissions for diarrhea.
    • Rotavirus is the single most important cause of dehydrating diarrhea in both developed and developing countries. It produces severe diarrhea, accounting for most episodes in children younger than 2 years who require hospitalization for diarrhea and dehydration.
    • Rotavirus incidence has a distinct seasonal pattern.
    • Rotavirus infection occurs most frequently in children aged 3-15 months and may occur in children as old as 24 months, although the vast majority of children have acquired antibodies by that age.
    • Rotavirus is transmitted by fecal oral spread with secondary spread via respiratory route.
  • Norwalk virus is responsible for outbreaks of gastroenteritis in older children and adults. Unlike rotavirus, which affects mainly children, the Norwalk virus causes illness in all age groups.
  • Enteric adenoviruses account for 5-20% of hospitalizations for acute diarrhea. Compared to rotavirus and Norwalk virus, enteric adenoviruses have a longer incubation period (ie, 8-10 d compared to 1-3 d), and the diarrhea associated with adenoviruses lasts longer (ie, 5-12 d compared to 5-7 d for rotavirus and 1-2 d for Norwalk). Astroviruses and caliciviruses each account for 3-5% hospitalizations for acute diarrhea.

    Additional information about viral gastroenteritis can be obtained from The Centers for Disease Control and Prevention (CDC).

• The most common bacterial agents in the United States are Salmonella, Shigella, Campylobacter, and Yersinia species and E coli. Enteroaggregative E coli has recently been shown to be an unrecognized cause of community-acquired diarrhea in infants in the United States. Campylobacter jejuni affects approximately 2 million people in the United States annually. Clostridium difficile is the most common cause of pseudomembranous colitis, a condition often observed in patients who develop severe diarrhea during or following a course of antibiotics. Clindamycin is the most common antibiotic identified, although almost all antibiotics have been implicated.
• • In patients with sickle cell disease, Salmonella species are the most frequent cause of gastroenteritis.
  • Giardia lamblia is the only parasite frequently isolated from patients with diarrhea. Other parasites include Cryptosporidium parvum and Cyclospora cayetanensis.
  • Nonpathogenic isolates are Entamoeba coli, Endolimax nana, Iodamoeba butschlii, and Blastocystis hominis.
  • In patients with HIV/AIDS, Mycobacterium avium is another causative agent, in addition to the other bacteria mentioned above. Protozoal agents include Cryptosporidium species, Isospora belli, G lamblia, Entamoeba histolytica, Cyclospora species, and microsporidia. Viral causes include cytomegalovirus and rotavirus.
  • Persistent infectious diarrhea may be caused by Shigella, Giardia, and Cryptosporidium species, EPEC, EAEC, and Entamoeba histolytica.
  • Additional information on bacterial foodborne and diarrheal diseases is available from the CDC.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Other Problems to be Considered

Chronic nonspecific diarrhea of childhood (toddler diarrhea)

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Lab Studies

• Most cases of children with mild-to-moderate dehydration require no laboratory tests. Electrolyte, BUN, serum creatinine, and glucose levels may be obtained for severely dehydrated children or those with atypical or inconsistent histories and physical examination results. Other laboratory tests may be ordered to assess hydration status, including hematocrit and urine specific gravity tests.
• Fecal leukocytes usually are observed in infections caused by invasive E coli and Shigella and Campylobacter species. This test's predictive value varies, as does that of occult blood testing.
• Gram stain of the stools may help differentiate infectious from noninfectious diarrhea. Gram-negative seagull-shaped bacteria visible with Gram stain strongly suggest campylobacteriosis. An ova and parasite examination and specialized staining procedures are necessary to diagnose a parasitic etiology.
• Stool cultures usually are reserved for cases of children with bloody diarrhea and those who are severely dehydrated, chronically ill or immunocompromised, or who have the appearance of toxemia.
• Metabolic acidosis with a normal anion gap occurs with loss of bicarbonate, including the following conditions:
• • Ureterostomy
  • Small bowel fistula
  • Extra chloride
  • Diarrhea
  • Carbonic anhydrase inhibitors
  • Early chronic renal failure
  • Addison disease
  • Renal tubular acidosis
  • Pancreatic fistula
  • Parenteral nutrition

Imaging Studies

• Although imaging studies are not routine for gastroenteritis, anatomical abnormalities (eg, obstruction) should be excluded in cases involving vomiting without diarrhea. Consider the possibility of intussusception in very young patients. Exclude an appendicitis diagnosis for patients in whom abdominal pain is a greater presenting symptom than diarrhea.

Histologic Findings

Stool examination for patients whose gastroenteritis is caused by invasive enteropathogens usually reveals small amounts of mucoid stools containing leukocytes, red blood cells, and/or gross blood. Both tests, however, have low specificity and are better used for their negative predictive value (ie, up to 95%). The probability of an invasive bacterial pathogen is very low when both test results are negative.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical Care

The American Academy of Pediatrics (AAP) states, "oral rehydration therapy is the preferred treatment of fluid and electrolytes lost by diarrhea in children with mild-to-moderate dehydration." In addition, both the AAP and the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) recommend rapid rehydration over 3-4 hours. A useful method is to administer 100 mL/kg/d for the first 10 kg of body weight (BW), 50 mL/kg for the next 10 kg BW, and 20 mL/kg for each additional kg BW.

The latest CDC recommendations for managing acute gastroenteritis in children can be viewed online at Managing Acute Gastroenteritis Among Children (King CK, 2003).

• Oral rehydration therapy in the home environment
• • Several oral rehydration solutions (ORSs) and pediatric maintenance solutions are available commercially (eg, Pedialyte, Rehydralyte, Kaolectrolyte, CeraLyte, Infalyte, Equalyte).
  • A general guideline is to provide 4-8 oz for every episode of loose or watery stools until the diarrhea resolves.
  • These fluids are not recommended for rehydration: tea, juices, pop, Kool-Aid, Gatorade (or similar sport drinks), boiled rice water, or boiled skim milk.
• Rehydration therapy in healthcare settings
• • Oral rehydration is possible in a doctor's office with available space for at least 4 hours monitoring, adequately trained staff, and adequate mechanisms for billing this service. Intravenous rehydration also is feasible in these settings for mildly dehydrated patients who do not tolerate oral rehydration.
  • Provide rapid intravenous rehydration for patients with the following conditions:
    • Severe dehydration with cardiovascular involvement (ie, hypotension or shock)
    • Failure of oral rehydration because of persistent vomiting
    • High stool output (ie, usually >10 mL/kg BW/h)
    • Monosaccharide malabsorption, evidenced by the presence of glucose or reducing substances in the stool and a significant increase in the stool volume following administration of the ORS
  • Cerebral edema is the most serious potential consequence of rapidly infusing hypotonic fluids in a patient with hypernatremic dehydration.
• Medications
  • Loperamide, opiates, opiate-and-atropine combination drugs, anticholinergic drugs, and absorbents are not recommended to treat diarrhea in children. No evidence exists that these are effective, and use may lead to possible adverse events.
  • Similarly, routine use of bismuth subsalicylate and lactobacillus-containing compounds is not recommended.
  • Most authorities do not recommend routine antiemetic use for children. Clinical evidence is currently insufficient to justify the use of ondansetron or metoclopramide in children with acute viral gastroenteritis.
  • While antibiotic treatment clearly shortens the clinical illness and duration of pathogen excretion in dysentery caused by Shigella species, routine antibiotic use provides no clear advantage to treat gastroenteritis caused by Campylobacter jejuni, Yersinia enterocolitica, E coli, and Salmonella species.
  • Antibiotic administration may be considered for very young patients with Salmonella-caused gastroenteritis, for patients who are immunocompromised, and for patients who are systemically ill.
  • Recent evidence suggests that antibiotic treatment of enterohemorrhagic E coli infection may increase the risk for developing hemolytic uremic syndrome.
  • Rifaximin has excellent antibacterial activity and was approved in 2004 for the treatment for traveler's diarrhea caused by noninvasive strains of E coli.

Diet

• Rapidly reintroducing normal feeding is the optimal rehydration method for children who are mildly to moderately dehydrated.
• For infants, the AAP, ESPGHAN, and other groups currently recommend full-strength formula. The recommended rehydration method for breastfed infants is to continue to receive mother's milk.
• For older children, the usual advice is to eat bananas, rice cereals, applesauce, and toast (ie, BRAT diet). Also on the recommended list are complex carbohydrates (eg, rice, wheat, bread, cereals), lean meats, yogurt, fruits, and vegetables.

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Drug Category: Antibiotics

In cases of Shigella enteritis, antibiotic treatment provides more rapid resolution of symptoms and faster fecal shedding of the organism. Trimethoprim-sulfamethoxazole (TMP-SMZ) is the drug of choice. In uncomplicated enteritis caused by nontyphoidal Salmonella species, antibiotics have no beneficial effect and may prolong the carrier state. The role of antimicrobials to treat enteritis caused by Campylobacter species, Y enterocolitica, and E coli remains controversial. Metronidazole is the recommended medication for G lamblia.

Drug Category: Vaccines

These agents elicit active immunization to increase resistance to infection. Vaccines consist of microorganisms or cellular components, which act as antigens. Administration of the vaccine stimulates the production of antibodies with specific protective properties.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Transfer

• Transfer by emergency medical service unit any patient with moderate-to-severe dehydration to the nearest emergency department for intravenous rehydration.

Prognosis

• Prognosis is excellent because gastroenteritis usually is self-limited. Children usually improve after an intravenous bolus. Patients who receive ORS improve gradually.

Patient Education

• For excellent patient education resources, visit eMedicine's Esophagus, Stomach, and Intestine Center. Also, see eMedicine's patient education article, Gastroenteritis.

MISCELLANEOUS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

Medical/Legal Pitfalls

• Failure to assess the extent of dehydration (sometimes due to insufficient information provided by parents who have telephoned the physician for advice)
• Failure by parents/patients to understand instructions
• Failure to schedule a follow-up visit
• Failure to diagnose ingestion(s)
• Failure to diagnose renal or acid-base abnormalities
• Failure to exclude anatomical abnormalities (eg, obstruction, abdominal infections)

Special Concerns

• Manage dehydration aggressively in patients who have sickle cell disease to prevent sequelae (eg, infarction, stroke, splenic sequestration). Administration of 1.5 times the normal rate of maintenance fluid infusion is a routine practice.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Miscellaneous
• References

• AAP. Practice parameter: the management of acute gastroenteritis in young children. Pediatrics. Mar 1996;97(3):424-35. [Medline].
• Amieva MR. Important bacterial gastrointestinal pathogens in children: a pathogenesis perspective. Pediatr Clin North Am. Jun 2005;52(3):749-77, vi. [Medline].
• CDC. Viral Gastroenteritis. Available at: http://www.cdc.gov/ncidod/dvrd/revb/gastro/faq.htm. Accessed April 24, 2006. [Full Text].
• CDC. Foodborne and Diarrheal Diseases Branch. Available at: http://www.cdc.gov/foodborne/. Accessed April 24, 2006. [Full Text].
• DeWitt TG, Humphrey KF, McCarthy P. Clinical predictors of acute bacterial diarrhea in young children. Pediatrics. Oct 1985;76(4):551-6. [Medline].
• DuPont HL. What's new in enteric infectious diseases at home and abroad. Curr Opin Infect Dis. Oct 2005;18(5):407-12. [Medline].
• Ericsson CD, DuPont HL. Rifaximin in the treatment of infectious diarrhea. Chemotherapy. 2005;51 Suppl 1:73-80. [Medline].
• Gastanaduy AS, Begue RE. Acute gastroenteritis. Clin Pediatr. Jan 1999;38(1):1-12. Review. [Medline].
• Gorelick MH, Shaw KN, Murphy KO. Validity and reliability of clinical signs in the diagnosis of dehydration in children. Pediatrics. May 1997;99(5):E6. [Medline]. [Full Text].
• Huicho L, Sanchez D, Contreras M, et al. Occult blood and fecal leukocytes as screening tests in childhood infectious diarrhea: an old problem revisited. Pediatr Infect Dis J. Jun 1993;12(6):474-7. [Medline].
• Jimenez SG, Heine RG, Ward PB, Robins-Browne RM. Campylobacter upsaliensis gastroenteritis in childhood. Pediatr Infect Dis J. Nov 1999;18(11):988-92. [Medline].
• King CK, Glass R, Bresee JS, et al. Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy. MMWR Recomm Rep. Nov 21 2003;52(RR-16):1-16. [Medline].
• Lasche J, Duggan C. Managing acute diarrhea: what every pediatrician needs to know. Contemp Pediatr. 1999;16(2):74-82.
• Liebelt EL. Clinical and laboratory evaluation and management of children with vomiting, diarrhea, and dehydration. Curr Opin Pediatr. Oct 1998;10(5):461-9. [Medline].
• Murphy MS. Guidelines for managing acute gastroenteritis based on a systematic review of published research. Arch Dis Child. Sep 1998;79(3):279-84. [Medline].
• Nataro JP. Treatment of bacterial enteritis. Pediatr Infect Dis J. May 1998;17(5):420-1. [Medline].
• Powell EC, Hampers LC. Physician variation in test ordering in the management of gastroenteritis in children. Arch Pediatr Adolesc Med. Oct 2003;157(10):978-83. [Medline].
• Szajewska H, Hoekstra JH, Sandhu B. Management of acute gastroenteritis in Europe and the impact of the new recommendations: a multicenter study. The Working Group on acute diarrhea of the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition. J Pediatr Gastroenterol Nutr. May 2000;30(5):522-7. [Medline].

Article Last Updated: Apr 25, 2008