Bacterial Gastroenteritis Treatment & Management

Because most infectious diarrhea is self-limited, medical care is primarily supportive in nature. Oral rehydration is the mainstay of treatment. Young infants and neonates are at 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.

• 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. 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 10-cc 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.
• Antimicrobial therapy is indicated for some bacterial gastroenteritis infections. However, many conditions are self-limited and do not require therapy. The following is a list of standard therapies:

  • Aeromonas species - Use cefixime and most third-generation and fourth-generation cephalosporins.
  • Bacillus species - No antibiotics are necessary for self-limited gastroenteritis, but vancomycin and clindamycin are first-line drugs for severe disease.
  • Campylobacter species - Erythromycin may shorten illness duration and shedding. Delaying therapy beyond 4 days from onset of symptoms appears to produce no clinical benefit.
  • C difficile - Discontinue potential causative antibiotics. If antibiotics cannot be stopped or this does not resolve diarrhea, use oral metronidazole or vancomycin. Vancomycin is reserved for seriously ill patients whose condition does not respond to metronidazole.
  • C perfringens - Do not treat with antibiotics.
  • E coli - Antibiotic treatment appears to increase the likelihood of HUS developing. Consider antibiotics if diarrhea is moderate or severe. Trimethoprim-sulfamethoxazole is a first-line drug, but use a parenteral second-generation or third-generation cephalosporin for systemic complications.
  • Listeria species - No antibiotics are needed unless invasive disease occurs. Ampicillin and Bactrim are first-line drugs for invasive disease.
  • Plesiomonas species - Use trimethoprim-sulfamethoxazole or any cephalosporin.
  • Salmonella species - Antibiotic treatment prolongs the carrier state and is associated with relapse; thus, treatment is not indicated for nontyphoid, uncomplicated diarrhea. Consider treatment for infants younger than 3 months and for high-risk patients, such as patients who are immunocompromised or who have sickle cell disease. Ampicillin is recommended for drug-sensitive strains. Trimethoprim-sulfamethoxazole, fluoroquinolones, or third-generation cephalosporins (fluoroquinolones are not recommended for use in children) are also acceptable alternatives. S typhimurium T104 is a multidrug-resistant organism. Sensitivities from the cultured specimens are important to guide therapy.
  • Shigella species - Antibiotic treatment may shorten illness duration and shedding but does not prevent complications. Most mild infections will recover without antibiotics. Moderate to severe cases should be treated with antibiotics. Ampicillin is preferred for drug-sensitive strains. For ampicillin resistant strains or in cases of penicillin allergy, trimethoprim-sulfamethoxazole is the drug of choice, although resistance does occur. Fluoroquinolones may be considered in patients with highly resistant organisms.
  • Vibrio cholerae - Tetracycline is the usual antibiotic of choice, but resistance to it is increasing. Other antibiotics that are effective when V cholerae are sensitive to them include cotrimoxazole, erythromycin, doxycycline, chloramphenicol, and furazolidone.
  • Yersinia species - Treatment (ie, trimethoprim-sulfamethoxazole, fluoroquinolones, aminoglycosides) does not shorten the disease duration and should be reserved for complicated cases.
• Antimotility agents are not indicated routinely for infectious diarrhea, (except for refractory cases of Cryptosporidium infection).
• Live Lactobacillus GG and heat-killed Lactobacillus LB reduce the duration of diarrhea in children when they are added to oral rehydration solution.^{[13, 14]}

• Certain organisms cause abdominal pain and bloody stools. Symptoms resembling appendicitis, hemorrhagic colitis, intussusception, or toxic megacolon may be appreciated. 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.

• 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.^{[15, 16, 17]}
• Introduce lean meats and clear fluids as soon as possible.^[15] Dairy products are said to be better absorbed when given with proteins or complex carbohydrates.
• When feeding lactose-containing dairy products, carefully monitor 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.