What is the best course of treatment for a patient with a history of colitis (inflammatory bowel disease) who presents with recent onset of yellowish diarrhea?

Management of Patient with History of Colitis and Recent Onset of Yellowish Diarrhea

For a patient with a history of colitis presenting with recent onset of yellowish diarrhea, the first step should be stool testing for infectious causes, followed by fecal lactoferrin/calprotectin testing, and early endoscopy with biopsy if inflammation markers are positive, while initiating appropriate medical therapy based on disease severity. 1

Initial Diagnostic Workup

Laboratory Testing

• Stool studies (priority):

  • Culture for bacterial pathogens (Shigella, Salmonella, Campylobacter)
  • C. difficile toxin assay (critical in patients with history of colitis)
  • Ova and parasites examination
  • Viral studies if indicated
  • Fecal lactoferrin and calprotectin (inflammatory markers) 2

• Blood tests:

  • Complete blood count (CBC) - to assess for anemia and leukocytosis
  • Comprehensive metabolic panel (CMP) - to evaluate electrolyte imbalances
  • C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) - inflammatory markers
  • Thyroid stimulating hormone (TSH) 2

Imaging and Procedures

• Endoscopy: Early colonoscopy or flexible sigmoidoscopy with biopsy within 2 weeks of symptom onset is strongly recommended, especially if fecal lactoferrin is positive 2
• CT scan of abdomen/pelvis: Consider if there are concerns for complications such as toxic megacolon, perforation, or abscess 2

Treatment Algorithm Based on Disease Severity

Mild Disease (< 4 stools/day above baseline)

1. Rule out infection first:

   • If infection confirmed, treat with pathogen-specific antibiotics 3
   • For suspected infectious colitis without confirmed pathogen, consider empiric azithromycin 1000mg single dose for adults with febrile dysenteric diarrhea 3

2. If infection ruled out and IBD flare confirmed:

   • First-line: Combination of topical mesalazine 1g daily plus oral mesalazine 2-4g daily 1
   • Second-line: Topical corticosteroids for patients intolerant to topical mesalazine 1
   • Consider hydration and loperamide only after infection ruled out 2

Moderate Disease (4-6 stools/day above baseline)

1. Hold immunotherapy if patient is on it 2
2. Initiate corticosteroids: Prednisolone 40mg daily with gradual tapering over 8 weeks 1
3. Consider gastroenterology consultation for further evaluation 2
4. If no improvement within 3 days: Consider adding biologics such as infliximab or vedolizumab 2

Severe Disease (≥7 stools/day above baseline)

1. Hospitalize patient for close monitoring 2
2. Multidisciplinary approach: Joint management by gastroenterologist and colorectal surgeon 2
3. Intravenous corticosteroids: Hydrocortisone 400mg/day or methylprednisolone 60mg/day 2
4. Consider early introduction of biologics: Infliximab 5mg/kg at 0,2, and 6 weeks, then every 8 weeks 4
5. Monitor for complications: Toxic megacolon, perforation, massive hemorrhage 2
6. Surgical evaluation: If no improvement within 48-72 hours of medical therapy, surgical consultation is mandatory 2

Special Considerations for Yellowish Diarrhea

The yellowish color of diarrhea specifically suggests:

• Possible bile acid malabsorption
• C. difficile infection (particularly important to rule out)
• Giardiasis or other parasitic infections
• Fat malabsorption

Common Pitfalls to Avoid

1. Delaying corticosteroid treatment while waiting for stool microbiology results in acute ulcerative colitis 1
2. Failing to consider joint medical and surgical management for severe ulcerative colitis 1
3. Overlooking thromboembolism risk in severe ulcerative colitis patients 1
4. Neglecting maintenance therapy in ulcerative colitis patients, which may increase colorectal cancer risk 1
5. Obscuring signs of worsening diarrhea with anti-motility agents before ruling out infection 2
6. Delaying endoscopy in patients with positive inflammatory markers, which can lead to longer symptom duration and steroid treatment 2

Follow-up Recommendations

• Close monitoring of symptoms, particularly if starting new therapy
• Repeat fecal calprotectin in 4-6 weeks to assess response to treatment
• Consider maintenance therapy with aminosalicylates, azathioprine, or mercaptopurine for long-term disease control 2
• Endoscopic reassessment to document mucosal healing in patients with moderate to severe disease 2

Remember that early intervention with appropriate therapy based on disease severity is crucial for improving outcomes and preventing complications in patients with colitis experiencing a flare.