Large Intestine: Infectious Colitis

Bacterial Infectious Colitis

Clostridioides difficile Colitis

Campylobacter jejuni

  • Gram Negative Rod (GNR)
  • Most Common Cause of Diarrheal Illness Worldwide
  • Source: Contaminated Food & Water
  • Causes Diffuse Bloody Edematous Enteritis
  • Sx: Abdominal Pain & Diarrhea – May Be Bloody
  • Dx: Stool Culture
  • Tx: ABX

Escherichia coli (E. coli)

  • Gram Negative Rod (GNR)
  • Most Common Aerobic Bacteria in Colon
  • Most Common Cause of GN Sepsis
  • Subtypes:
    • Enterotoxigenic
      • Most Common Cause of Traveler’s Diarrhea
    • Enterohemorrhagic
      • Two Strains (O157:H7 & Non-O157:H7)
      • Produces Shiga-Like Toxins & Bloody Diarrhea
      • Source: Contaminated Beef
      • Responsible for Hemolytic-Uremic Syndrome (HUS)
    • Enteropathogenic
    • Enteroaggregative
    • Enteroinvasive

Salmonella

  • Gram Negative Rod (GNR)
  • Source: Egg, Poultry & Milk
  • Sx:
    • Diarrhea – May Be Bloody
    • Nausea & Vomiting
    • Abdominal Pain
    • Fever
  • Generally Resolves within 4-10 Days
  • Dx: Stool Culture – Not Always Warranted
  • Tx: Fluid Resuscitation & ABX if Severe

Shigella

  • Gram Negative Rod (GNR)
  • Source: Person-to-Person or Contaminated Food-Water
    • Commonly Seen in Overcrowding
  • Sx:
    • Abdominal Pain
    • Dysentery – Bloody & Mucoid Diarrhea
    • Fever
    • Nausea & Vomiting
  • May Also Cause Hemolytic-Uremic Syndrome (HUS)
  • Dx: Stool Culture
  • Tx: Fluid Resuscitation & ABX

Yersinia enterocolitica

  • Gram Negative Rod (GNR)
  • Source: Contaminated Pork
  • Common in Young Children During the Winter
  • Sx:
    • Abdominal Pain
    • Diarrhea
    • Fever
    • Nausea & Vomiting
  • Can Mimic Appendicitis (Pseudoappendicitis)
    • From Acute Mesenteric Lymphadenitis
  • Dx: Stool Culture
  • Tx: Unclear – Consider ABX

Actinomyces israelii

  • Gram Positive Rod (GPR)

Mycobacterium tuberculosis

  • Third Most Common Extra-Pulmonary Site

Campylobacter jejuni 1

Escherichia coli 1

Salmonella 1

Enteric Gram Negative Rods 2

Viral Infectious Colitis

Cytomegalovirus (CMV)

  • Bloody Diarrhea
  • Most Common in Immunocompromised (AIDS)
    • Most Common Secondary to Reactivation of Latent Infections Rather than Primary Infection
  • Sx: Abdominal Pain, Diarrhea – Often Bloody & Fever
  • Can Cause Toxic Megacolon & Necrotizing Infection
  • Dx: Endoscopic Bx (Large Atypical Cells with Intranuclear Inclusion Bodies)
  • Tx: Ganciclovir

Other Viral Causes

  • Norovirus
  • Rotavirus
  • Adenovirus

Parasitic Infectious Colitis

Entamoeba histolytica (Amoebic Colitis)

  • Source: Contaminated Food & Water
  • Generally Migrants/Travelers From Endemic Areas
    • Endemic Areas: Mexico, Central/South America, Africa & India
    • Common “Mexico Connection”
  • Sites
  • Dx: Stool Testing (Antigen or PCR) or Endoscopic Bx (Ulcers & Trophozoites)
  • Tx: Flagyl

Giardia (Giardiasis)

  • Source: Fecal Contamination
  • Sx: Bloating, Flatulence, Diarrhea & Steatorrhea
  • Commonly When Camping or in Daycare

Entamoeba histolytica 3

Giardia 4

References

  1. Wikimedia Commons. (License: Public Domain)
  2. Domangue B. Wikimedia Commons. (License: CC BY-SA-4.0)
  3. Cann A. Wikimedia Commons. (License: CC BY-SA-2.0)
  4. Walkowski S. Wikimedia Commons. (License: CC BY-SA-4.0)