Infectious Colitis / Enteritis / Gastroenteritis

  • CC: Diarrhea, abdominal pain

  • PP: Fever, nausea/vomiting, dehydration, watery or bloody diarrhea, recent travel, sick contacts, food exposure, diffuse abdominal cramping

  • PN: No focal peritonitis unless severe colitis/perforation concern

  • pertinent SHx: Recent antibiotics, travel, contaminated food/water exposure, immunocompromised state

  • Etiology: Infectious inflammation of bowel from bacterial, viral, or parasitic pathogen; colitis predominantly affects colon while enteritis predominantly affects small bowel

  • risk factors: Recent antibiotics, hospitalization, travel, immunocompromised state, contaminated food/water exposure

  • initial DATA: CBC (WBC↑), BMP/CMP, stool PCR/culture, C. diff testing if indicated, lactate if severe/septic, CT A/P if severe abdominal pain/peritonitis concern

  • pending DATA: Stool studies, O&P if prolonged/travel-related, blood cultures if febrile/septic

  • MEDS: Recent antibiotics, immunosuppressants, PPIs

  • COURSE:

Plan:

  • IVF + electrolyte repletion

  • Contact precautions if infectious diarrhea/C. diff concern

  • Avoid antimotility agents if bloody diarrhea/high fever/invasive bacterial concern

  • Mild/supportive:

    • Usually supportive care only

  • Severe bacterial/traveler’s diarrhea:

    • Azithromycin 500 mg daily

    • OR Ciprofloxacin 500 mg PO BID

  • Severe/septic colitis:

    • Ceftriaxone 2 g IV daily + Metronidazole 500 mg IV q8h

  • C. diff concern:eritis

    • Oral Vancomycin or Fidaxomicin

  • Trend CBC/BMP/stool output/fever curve

  • Follow stool studies and narrow antibiotics

  • GI consult if toxic megacolon, severe bleeding, perforation, or severe colitis

  • Escalate ICU if shock/toxic megacolon/perforation/severe dehydration

  • Duration:

    • Usually 3–7 days depending organism/severity

    • C. diff typically 10 days

Main Difference:

  • Colitis more commonly causes inflammatory/bloody diarrhea from colon involvement, while enteritis more commonly causes watery diarrhea with nausea/vomiting from small bowel involvement. Gastreoent