What is the initial treatment approach for infectious transverse colitis not related to Clostridioides (C. difficile)?

Initial Treatment of Infectious Transverse Colitis (Non-C. difficile)

For infectious transverse colitis not related to C. difficile, empiric antibiotic therapy with azithromycin 1000 mg as a single dose should be initiated immediately for suspected invasive bacterial pathogens (Shigella, Salmonella, Campylobacter), while simultaneously obtaining stool cultures to guide pathogen-specific therapy. 1

Diagnostic Approach

Immediate stool studies are essential:

• Standard stool culture for invasive bacterial enteropathogens (Shigella, Salmonella, Campylobacter) 1
• Test for Shiga toxin-producing E. coli (STEC) directly in stool if dysentery is present with low-grade or absent fever 1
• Stool inflammatory markers (leukocytes, lactoferrin, or calprotectin) to confirm inflammatory colitis 1
• Consider specialized studies based on epidemiologic clues: recent international travel, shellfish consumption, or residence in parasite-endemic regions 1

Treatment Algorithm

Empiric Therapy (Before Culture Results)

For febrile dysenteric diarrhea:

• Azithromycin 1000 mg single dose orally for adults 1
• This covers the most common invasive bacterial enteropathogens (Shigella, Salmonella, Campylobacter) 1

Critical caveat: Do NOT treat empirically if STEC is suspected (dysentery with minimal or no fever), as antibiotics may increase risk of hemolytic uremic syndrome 1

Pathogen-Specific Therapy (After Culture Results)

Once laboratory diagnosis confirms a specific pathogen:

• Initiate pathogen-specific antimicrobial therapy for all forms of infectious colitis except STEC 1
• Adjust antibiotics based on culture sensitivities and local resistance patterns 1

Supportive Management

Discontinue inciting antibiotics if possible:

• Stop any broad-spectrum antibiotics that may have precipitated the colitis 2, 3
• If continued antibiotic therapy is required for another indication, choose agents less associated with infectious complications 2

Avoid medications that may worsen colitis:

• Do not use antiperistaltic agents or opiates 3
• Discontinue proton pump inhibitors if not medically necessary 3

Fluid and electrolyte management:

• Intravenous fluid and electrolyte replacement to correct dehydration 4
• Monitor vital signs and clinical status closely 4

Monitoring and Escalation

Daily assessment should include:

• Physical examination for abdominal tenderness and peritoneal signs 4
• Stool frequency and character documentation 4
• Complete blood count, inflammatory markers (CRP or ESR), electrolytes, and renal function every 24-48 hours 4
• Abdominal imaging if clinical deterioration occurs or colonic dilatation is suspected 4

Consider surgical consultation if:

• Signs of perforation, toxic megacolon (transverse colon >6 cm), or severe ileus develop 4, 3
• Systemic inflammation with deteriorating clinical condition despite appropriate antibiotic therapy 4, 3

Common Pitfalls

• Do not delay empiric antibiotics while waiting for stool culture results in patients with fever and dysentery 1
• Do not treat STEC with antibiotics as this increases complications; confirm pathogen first if suspicion is high 1
• Do not assume all infectious colitis requires antibiotics—STEC is a notable exception 1
• Maintain high clinical suspicion for alternative diagnoses including inflammatory bowel disease if symptoms persist despite appropriate antimicrobial therapy 4