Approach Considerations
Because most infectious diarrhea is self-limited, medical care is primarily supportive in nature. Oral rehydration therapy is the cornerstone of diarrhea treatment, especially for small bowel infections that produce a large volume of watery stool output. Studies confirm that early refeeding hastens recovery. Many commercial oral rehydration formulas are available and have been designed to promote optimal absorption of nutrients.
Young infants and neonates are at a high risk for secondary complications and require close monitoring, as do older individuals.
Consider intravenous rehydration when oral rehydration is unsuccessful. Particular attention must be paid to repletion of potassium as needed.
Administer maintenance fluids plus replacement of losses to ill children. Administer small amounts of fluid at frequent intervals in order to minimize discomfort and vomiting. A 5 or 10cc syringe without a needle is a very useful tool. The syringe can be used to place small amounts of fluid in the mouth quickly. Once the patient becomes better hydrated, cooperation improves enough for the patient to take small sips from a cup. This method is time intensive and requires dedication. Encouragement from the physician is necessary to promote compliance.
Live Lactobacillus GG and heat-killed Lactobacillus LB reduce the duration of diarrhea in children when they are added to oral rehydration solution. [1, 2] A systematic review and meta-analysis of 31 randomized-controlled trials comprising 8672 children and adults suggests with moderate certainty that probiotics are effective for preventing C difficile-associated diarrhea and that short-term use of probiotics in conjunction with antibiotics appears to be safe in those who are immunocompetent and those who aren't severely debilitated. [45] Adverse effects appeared in 32 trials assessed, but they were more common in the control groups.
Antimicrobial therapy is indicated for some bacterial gastroenteritis infections. However, many conditions are self-limited and do not require therapy.
Antimotility agents are not indicated routinely for infectious diarrhea (except for refractory cases of Cryptosporidium infection).
Inpatient care
Admit neonates or young infants with moderate dehydration, suspected infection with enterohemorrhagic E coli, or bloody diarrhea.
Oral rehydration in cases of gastroenteritis is a time-consuming task that requires vigilance. Evaluate the caretaker of a child who requires oral rehydration for compliance. Consider admission if any doubt exists regarding potential compliance.
Older patients, often with other illnesses, require careful observation and consideration for admission.
Consultations
Certain organisms cause abdominal pain and bloody stools. Symptoms resembling appendicitis, hemorrhagic colitis, intussusception, or toxic megacolon may be observed. In such cases, obtain a consultation with a surgeon.
Consider consultation with an infectious disease specialist, especially for any patient who is immunocompromised due to human immunodeficiency virus (HIV) infection, chemotherapy, or immunosuppressive drugs, because atypical organisms are more likely and complications can be more serious and can fulminate.
Diet
Although some claim that changes in dietary regimen are not necessary, improper diet can result in prolonged recovery or development of carbohydrate malabsorption, especially if the acute episode is overshadowed by an undiagnosed chronic bacterial or malabsorption syndrome.
Thus, a prolonged course of diarrhea should prompt investigation of complicating factors. Results from tests such as stool acidity and reducing substances can indicate carbohydrate malabsorption. Failure to recognize this complication can result in significant rapid weight loss with wasting of fat and muscle mass.
Dietary considerations
The BRAT diet (ie, bananas, rice, applesauce, toast) has been recommended for years in cases of gastroenteritis. This diet is adequate during early convalescence, but, as the patient tolerates solid food, advance the diet to provide adequate protein and caloric intake. [3, 25, 26]
Introduce lean meats and clear fluids as soon as possible. [3] Dairy products are said to be better absorbed when given with proteins or complex carbohydrates.
When feeding lactose-containing dairy products, carefully monitor the patient for signs of malabsorption.
Breast milk contains many substances that promote bowel growth and antagonize bacteria; thus, continue breastfeeding throughout the illness for infants.
Follow-Up
Follow-up care in cases of bacterial gastroenteritis depends on the severity of the infection and the age of the patient. Uncomplicated diarrhea may not require follow-up if the patient or caretaker is reliable and has adequate access to medical care if needed.
Monitor young children, elderly patients, and debilitated individuals closely to ensure that complications do not occur. Monitor patients requiring labor-intensive oral rehydration to ensure that the proper diet has been reintroduced.
Neonates require strict follow-up care within a few days of the illness to ensure that malabsorption and dehydration do not occur.
Deterrence and Prevention
Avoidance of undercooked meats and seafood, as well as contaminated water supplies, when traveling may help to reduce the risk of transmission of food and water-borne infectious causes of gastroenteritis and associated symptoms.
Vaccines
Salmonella typhi vaccine is recommended for travelers to countries with a high incidence of this infection, persons with intimate exposure to a documented typhoid fever carrier, and workers with frequent exposure to these bacteria. Live attenuated, killed whole-cell, and capsular polysaccharide vaccines are available.
Vibrio vaccine is available but only protects 50% of immunized persons for 3-6 months. It is not indicated for widespread use.
In February 2006, the US Food and Drug Administration (FDA) approved an oral vaccine for rotavirus (RotaTeq) for use in infants. On Feb 21, 2006, the American Academy of Pediatrics (AAP) and the Advisory Committee on Immunization Practices (ACIP) recommended that RotaTeq be part of regularly scheduled childhood immunizations. The vaccine is administered in a 3-dose series starting between ages 6 and 12 weeks and ending before age 32 weeks.
Clinical trials of RotaTeq demonstrated prevention of 74% of all rotavirus gastroenteritis cases, of nearly all severe rotavirus gastroenteritis cases, and of nearly all hospitalizations. A previously marketed rotavirus vaccine (RotaShield) was associated with intussusception, but RotaTeq did not show an increased risk compared with placebo in clinical trials.
In April 2008, the FDA approved Rotarix, another oral vaccine, for prevention of rotavirus gastroenteritis. It is currently recommended that Rotarix be administered in 2 separate doses to patients between ages 6 and 24 weeks. Rotarix was efficacious in a large study, which showed that it protected patients with severe rotavirus gastroenteritis and also decreased the rate of severe diarrhea or gastroenteritis from any cause. [27]
Tables
Stool Characteristics |
Small Bowel |
Large Bowel |
Appearance |
Watery |
Mucus and/or blood |
Volume |
Large |
Small |
Frequency |
Increased |
Increased |
Blood |
Possibly heme-positive but never gross blood |
Possibly grossly bloody |
pH |
Possibly < 5.5 |
>5.5 |
Reducing substances |
Possibly positive |
Negative |
White blood cell (WBC) count |
< 5/high-power field (HPF) |
Possibly >10/HPF |
Serum WBC count |
Normal |
Possible leukocytosis, bandemia |
Organisms |
Preformed toxins: Bacillus species, Staphylococcus aureus |
Invasive bacteria: E coli and Shigella, Salmonella, Campylobacter, Yersinia, Aeromonas, and Plesiomonas species |
Toxic bacteria: E coli, cholera, C perfringens, Vibrio species, Listeria monocytogenes |
Toxic bacteria: C difficile |
|
Other causes: rotavirus, adenovirus, calicivirus, astrovirus, Norwalk virus, and Giardia and Cryptosporidium species |
Other causes: Entamoeba species |
Organism |
Incubation |
Duration |
Vomiting |
Fever |
Abdominal Pain |
Aeromonas species |
None |
0-2 weeks |
+/- |
+/- |
No |
Bacillus species |
1-16 hours |
1-2 days |
Yes |
No |
Yes |
Campylobacter species |
2-4 days |
5-7 days |
No |
Yes |
Yes |
C difficile |
Variable |
Variable |
No |
Few |
Few |
C perfringens |
0-1 |
1 day |
Mild |
No |
Yes |
Enterohemorrhagic E coli |
1-8 days |
3-6 days |
No |
+/- |
Yes |
Enterotoxigenic E coli |
1-3 days |
3-5 days |
Yes |
Low |
Yes |
Listeria species |
20 hours |
2 days |
Few |
Yes |
+/- |
Plesiomonas species |
None |
0-2 weeks |
+/- |
+/- |
+/- |
Salmonella species |
0-3 days |
2-7 days |
Yes |
Yes |
Yes |
Shigella species |
0-2 days |
2-7 days |
No |
High |
Yes |
S aureus |
2-6 hours |
1 day |
Yes |
No |
Yes |
Vibrio species |
0-1 days |
5-7 days |
Yes |
No |
Yes |
Y enterocolitica |
0-6 |
1-46 days |
Yes |
Yes |
Yes |
Organism |
Detection Method |
Microbiologic Characteristics |
Aeromonas species |
Blood agar |
Oxidase-positive, flagellated GNB |
Bacillus species |
Blood agar |
Facultatively aerobic, spore-forming GPR; beta hemolytic; reduces nitrates; ferments carbohydrates |
Campylobacter species |
Skirrow agar |
Rapidly motile, curved GNR; Campylobacter jejuni 90% of infections, Campylobacter coli 5% of infections |
C difficile |
CCFE agar, EIA for toxin, LA for protein |
Anaerobic, spore-forming GPR; toxin-mediated diarrhea; produces pseudomembranous colitis |
C perfringens |
None available |
Anaerobic, spore-forming GPR; toxin-mediated diarrhea |
E coli |
MacConkey, EMB, or SM agar |
Lactose-producing GNR |
Listeria species |
Blood agar |
Flagellated GPB |
Plesiomonas species |
Blood agar |
Oxidase-positive GNR |
Salmonella species |
Blood, MacConkey, EMB, XLD, or HE agar |
Nonlactose, non–H2S-producing GNR |
Shigella species |
Blood, MacConkey, EMB, XLD, or HE agar |
Nonlactose and H2S-producing GNR; verotoxin (neurotoxin) |
Staphylococcus species |
Blood agar |
Heat-stable, preformed toxin-mediated GPC |
Vibrio species |
Blood or TCBS agar |
Oxidase-positive, motile, curved GNB |
Y enterocolitica |
CIN agar |
Nonlactose-producing, oval GNR |
CCFE = cycloserine-cefoxitin-fructose-egg; CIN = cefsulodin-irgasan-novobiocin; EIA= enzyme immunoassay; EMB = e-methylene blue; GNB = gram-negative bacillus; GNR = gram-negative rod; GPB = gram-positive bacillus; GPC = gram-positive cocci; GPR = gram-positive rod; H2S = hydrogen sulfide; HE = Hektoen enteric; LA = latex agglutination; SM = Sorbitol-MacConkey; TCBS = thiosulfate-citrate-bile-sucrose; XLD = xylose-lysine-deoxycholate. |
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