Viral gastroenteritis

See Acute gastroenteritis (peds) for pediatric patients

Background

• Most common cause of acute gastroenteritis (AGE)
• Viral gastroenteritis usually lasts <7d
• Do NOT diagnosis isolated vomiting as AGE!

Clinical Features

• Vomiting
• Watery, non-bloody diarrhea
• Crampy/diffuse abdominal pain
• Features that suggest non-viral etiology:
  • Bloody diarrhea (Salmonella, shigella)
  • RLQ pain (Yersina, Entamoeba)
  • Recent antibiotics + copious, foul diarrhea (C. Diff)
  • Consumption of previously cooked/reheated foods (especially meats, mayonaise, etc.)
  • Explosive, "rice-water" diarrhea (cholera)
  • bloating, really nasty flatus/stools (giardia)

Differential Diagnosis

Diffuse Abdominal pain

• Abdominal aortic aneurysm
  • Aortocaval fistula
• Acute gastroenteritis
• Aortoenteric fisulta
• Appendicitis (early)
• Bowel obstruction
  • Large bowel obstruction
    • Ogilvie's syndrome
  • Small bowel obstruction
  • Malignant bowel obstruction
• Bowel perforation
• Diabetic ketoacidosis
• Gastroparesis
• Hernia
• Hypercalcemia
• Inflammatory bowel disease
• Mesenteric ischemia
  • Mesenteric vein thrombosis
• Pancreatitis
• Peritonitis
• Sickle cell crisis
• Spontaneous bacterial peritonitis
• Volvulus

Nausea and vomiting

Critical

• ACS/MI
• Boerhaave's
• DKA
• Intracranial hemorrhage
• Ischemic bowel
• Meningitis
• Sepsis

Emergent

• Acute radiation syndrome
• Acute gastric dilation
• Adrenal insufficiency
• Appendicitis
• Bowel obstruction/ileus
• Carbon monoxide poisoning
• Cholecystitis
• CNS tumor
• Electrolyte abnormalities
• Elevated ICP
• Gastric outlet obstruction, gastric volvulus
• Hyperemesis gravidarum
• Medication related
  • Acetaminophen toxicity
  • Aspirin toxicity
  • Digoxin toxicity
  • Theophylline toxicity
  • GLP-1 receptor agonist toxicity
• Pancreatitis
• Peritonitis
• Ruptured viscus
• Testicular torsion/ovarian torsion

Nonemergent

• Acute gastroenteritis
• Biliary colic
• Cannabinoid hyperemesis syndrome
• Chemotherapy
• Cyclic vomiting syndrome
• ETOH
• Gastritis
• Gastroenteritis
• Gastroparesis
• Hepatitis
• Labyrinthitis
• Migraine
• Medication related
  • Disulfiram effect
  • Erythromycin
  • Ibuprofen
  • Ipecac toxicity
• Motion sickness
• Narcotic withdrawal
• Thyroid
• Pregnancy
• Peptic ulcer disease
• Renal colic
• UTI

Evaluation

• Assess hydration status
  • Cap refill, skin turgor, respiratory rate
• Consider stool studies if:
  • >10 stools in previous 24hr
  • Travel to high-risk country
  • Fever
  • Bloody stool
  • Persistent diarrhea

Management

1. Rehydration (PO preferred)
   • 30mL(1oz)/kg/hr
2. Antiemetic
   • Ondansetron 0.15mg/kg/dose IV/PO
3. Antibiotics
   • Only consider in patients with invasive infection
     • Shigella, campylobacter, E. coli, yersinia, vibrio
     • Bloody stool with mucus and fever
   • NOT indicated for E. coli O157:H7
   • NOT routinely indicated for salmonella
     • Exceptions: SCD, IBD, <3mo
   • Azithromycin (able to tolerate PO)
   • OR ciprofloxacin
   • OR TMP-SMX
   • Ceftriaxone (parenteral)

Disposition

• Most can be discharged
• Admit
  • Unable to tolerate PO
  • Hemodynamic instability
  • Significant comorbidities

See Also

• Acute gastroenteritis
• Nausea and Vomiting
• Acute gastroenteritis (peds)
• Dehydration
• Acute diarrhea