What is the treatment approach for enteritis?

Treatment Approach for Enteritis

The treatment of enteritis depends critically on the clinical context: uncomplicated infectious enteritis requires primarily supportive care with oral rehydration and selective antimicrobial therapy based on severity and risk factors, while neutropenic enteritis demands immediate broad-spectrum antibiotics with bowel rest, and surgery is reserved only for complications like perforation or ischemia. 1

Initial Assessment and Risk Stratification

Determine illness severity and patient risk factors to guide management intensity:

• Mild-to-moderate uncomplicated diarrhea: Patients without fever, blood in stool, severe dehydration, or immunocompromise can be managed conservatively 1
• Complicated diarrhea: Presence of fever documented in medical setting, bloody diarrhea, severe abdominal pain, signs of sepsis, immunocompromise, or dehydration requires aggressive intervention 1
• High-risk hosts: Immunocompromised patients (neutropenic, HIV-infected, post-transplant) require lower threshold for hospitalization and empiric antibiotics 1, 2

Supportive Care (Foundation of All Treatment)

Rehydration Therapy

• Reduced osmolarity oral rehydration solution (ORS) is first-line for mild-to-moderate dehydration in all age groups 1
• Nasogastric ORS may be considered for moderate dehydration when oral intake is not tolerated 1
• Intravenous isotonic fluids (lactated Ringer's or normal saline) are indicated for severe dehydration, shock, altered mental status, ORS failure, or ileus 1
• Potassium supplementation of at least 60 mmol/day is usually necessary; hypokalaemia can promote toxic dilatation 1

Symptomatic Management

• Loperamide (4 mg initially, then 2 mg after each loose stool, maximum 16 mg/day) for uncomplicated diarrhea 1
• Avoid antidiarrheal agents in patients with high fever, bloody diarrhea, or suspected invasive pathogens 1
• Avoid anticholinergic, antidiarrhoeal, and opioid agents in neutropenic enterocolitis as they may aggravate ileus 1

Antimicrobial Therapy: When and What

Empiric Antibiotic Indications

Empiric antibiotics are appropriate in specific scenarios:

• Traveler's diarrhea: Fluoroquinolone (adults) or trimethoprim-sulfamethoxazole (children) can reduce illness duration from 3-5 days to <1-2 days 1
• Bloody diarrhea with fever and systemic illness: Empiric therapy while awaiting culture results 1
• Infants <3 months with suspected bacterial etiology 1
• Recent international travel with fever ≥38.5°C or signs of sepsis 1
• Immunocompromised patients with severe illness and bloody diarrhea 1

Empiric Antibiotic Selection

• Adults: Fluoroquinolone (ciprofloxacin) or azithromycin, depending on local susceptibility patterns and travel history 1
• Children: Third-generation cephalosporin for infants <3 months or those with neurologic involvement; azithromycin based on local patterns 1
• Complicated cases: Consider adding metronidazole for anaerobic coverage 1

Critical Caveat: STEC Infections

Avoid antimicrobials in STEC O157 and other Shiga toxin 2-producing strains, as antibiotics may increase risk of hemolytic uremic syndrome 1

Special Clinical Scenarios

Neutropenic Enteritis/Enterocolitis

This is a medical emergency with high mortality requiring aggressive non-operative management:

• Immediate broad-spectrum antibiotics upon diagnosis confirmation (bowel wall thickening >5 mm on imaging) 1, 2
• First-line regimen: Monotherapy with anti-pseudomonal β-lactam (piperacillin-tazobactam), carbapenem, or cefepime/ceftazidime plus metronidazole 1
• Coverage required: Enteric gram-negatives (Pseudomonas, E. coli), gram-positives (Staphylococcus aureus, GAS), and anaerobes 1
• Bowel rest with nasogastric decompression and IV fluids 1
• G-CSF administration to accelerate neutrophil recovery 1
• Adjunct antifungal therapy (amphotericin) if no improvement after antibacterial therapy, as fungemia is common 1
• Resolution occurs in 86% with conservative treatment in median 6-8 days; neutrophil count recovery correlates with symptom resolution 1, 2

Surgery is reserved only for perforation, uncontrolled bleeding after correction of coagulopathy, abscess formation, or clinical deterioration despite aggressive medical management 1

CMV Enteritis/Colitis

• Non-operative management with antiviral therapy (ganciclovir), broad-spectrum antibiotics, and bowel rest 2
• CMV prophylaxis with ganciclovir for prolonged periods post-transplant 1
• Emergency surgery reserved only for toxic megacolon, fulminant colitis, perforation, or ischemia 2
• Consider CMV in post-transplant patients or those with severe UC not responding to steroids; confirm with antigenemia assay 1

Severe Ulcerative Colitis with Infectious Complications

• IV corticosteroids (methylprednisolone 60 mg/24h or hydrocortisone 100 mg four times daily) remain first-line 1
• Mandatory stool evaluation for C. difficile, which is more prevalent and associated with increased mortality 1
• Oral vancomycin if C. difficile detected; consider fecal microbial transplant 1
• Flexible sigmoidoscopy with biopsy to exclude CMV infection, which requires specific antiviral treatment 1

Clostridioides difficile

• Test specifically in cases of nosocomial diarrhea (≥3 days after hospitalization) or recent antibiotic exposure 1, 2
• Treatment should follow established C. difficile guidelines (oral vancomycin or fidaxomicin preferred over metronidazole) 1

Diagnostic Testing to Guide Therapy

When to Test

Obtain stool studies for:

• Diarrhea lasting >1 day with fever, bloody stools, or systemic illness 1
• Recent antibiotic use, day-care attendance, hospitalization, or dehydration 1
• Immunocompromised patients 2
• Nosocomial diarrhea ≥3 days after admission 1

What to Test

• Stool culture and sensitivity for bacterial pathogens (Salmonella, Shigella, Campylobacter, E. coli) 1
• C. difficile toxin assay for nosocomial or antibiotic-associated diarrhea 1, 2
• Ova and parasite examination for persistent diarrhea or travel history 2
• Fecal leukocytes or lactoferrin to identify inflammatory diarrhea 1
• Blood cultures in febrile patients with suspected enteric fever or sepsis 1

Imaging in Special Populations

• CT scan is most reliable for diagnosing neutropenic enteritis; bowel wall thickening >10 mm predicts 60% mortality vs. 4.2% if <10 mm 1, 2
• Ultrasound can detect bowel wall thickening >5 mm in neutropenic enteritis 1

Modifying Therapy Based on Pathogen Identification

Antimicrobial treatment should be modified or discontinued when a specific organism is identified 1

• Shigella: Treat with appropriate antibiotics based on susceptibility 1
• Salmonella gastroenteritis: Generally avoid antibiotics in uncomplicated cases in healthy hosts, as they may prolong carrier state 3
• Campylobacter: Azithromycin or fluoroquinolone if severe 1
• Giardia: Metronidazole or tinidazole for persistent diarrhea >10-14 days with suggestive history 1
• Cryptosporidium/Microsporidium: Particularly important in HIV-infected patients; may require specific antiparasitic therapy 2

Common Pitfalls to Avoid

• Do not delay rescue therapy in severe colitis; decisions should be made by Day 3 of steroid therapy to avoid high morbidity from prolonged ineffective treatment 1
• Do not use antibiotics empirically for all bloody diarrhea; STEC infections may worsen with antimicrobial therapy 1
• Do not delay surgery in neutropenic enteritis with perforation or progressive deterioration; mortality approaches 81% with delayed intervention 1
• Clinical signs are unreliable in immunocompromised patients; maintain high index of suspicion and use imaging liberally 1, 2
• Laboratory values may not reflect severity in immunocompromised hosts; clinical judgment and imaging are critical 2