What is Colotis and how is it treated?

Colitis: Definition and Treatment

"Colitis" refers to inflammation of the colon, which encompasses several distinct conditions including ulcerative colitis (UC), Crohn's disease affecting the colon, microscopic colitis (collagenous and lymphocytic), infectious colitis, and immunotherapy-related colitis—each requiring specific diagnostic confirmation and tailored treatment approaches.

What is Colitis?

Colitis is inflammation of the colon that can result from multiple etiologies 1, 2:

• Ulcerative colitis: Chronic inflammatory condition causing continuous mucosal inflammation starting in the rectum and extending proximally, characterized by bloody diarrhea, abdominal pain, urgency, and tenesmus 3, 1
• Crohn's disease of the colon: Can affect any part of the colon with skip lesions, may involve stricturing or fistulating patterns 3
• Microscopic colitis: Includes collagenous and lymphocytic colitis, causing chronic watery diarrhea with normal-appearing mucosa endoscopically but characteristic histologic findings 4, 5
• Infectious colitis: Caused by viruses, bacteria, or parasites, typically acute onset 6
• Immunotherapy-related colitis: Complication of immune checkpoint inhibitors 3

Diagnostic Approach

Before initiating treatment, confirm the diagnosis through endoscopy with biopsies, exclude infectious causes with stool studies (including C. difficile), and assess disease extent and severity 3, 7, 8.

Key diagnostic steps include:

• Endoscopic evaluation: Colonoscopy or sigmoidoscopy to assess extent, pattern, and severity of inflammation 3, 2
• Histopathology: Multiple biopsies to confirm chronic inflammation and distinguish between UC, Crohn's disease, and microscopic colitis 3, 1
• Stool studies: Rule out infectious causes before escalating immunosuppressive therapy 7, 8
• Laboratory assessment: Complete blood count, inflammatory markers (ESR, CRP), electrolytes, albumin 3

Treatment Based on Colitis Type and Severity

Ulcerative Colitis Treatment

Mild to Moderate Disease

For distal colitis (proctitis and left-sided disease), combination therapy with oral mesalazine 2-4g daily plus topical mesalazine 1g daily is first-line treatment 7:

• Proctitis: Topical mesalazine suppositories are preferred initial therapy 7
• Left-sided colitis: Mesalazine enemas combined with oral mesalazine 7
• Extensive colitis/pancolitis: Oral mesalazine 2-4g daily or balsalazide 6.75g daily, often combined with topical therapy 9
• Once-daily dosing is as effective as divided doses and improves adherence 7, 9

If no improvement after 2-3 weeks of optimized aminosalicylate therapy, initiate oral prednisolone 40mg daily with gradual taper over 8 weeks 7, 9:

• Topical agents may continue as adjunctive therapy 3, 7
• Rapid steroid tapering increases relapse risk and should be avoided 3, 8

Severe Ulcerative Colitis

Patients meeting Truelove and Witts criteria for severe disease require immediate hospitalization for intensive intravenous therapy with joint gastroenterology-surgical management 3:

Essential management components include:

• Intravenous corticosteroids: Hydrocortisone 400mg/day or methylprednisolone 60mg/day 3
• Daily monitoring: Physical examination for peritoneal signs, vital signs four times daily, stool chart documenting frequency and blood 3
• Laboratory surveillance: CBC, CRP, electrolytes, albumin every 24-48 hours 3, 9
• Imaging: Daily abdominal X-ray if colonic dilatation >5.5cm detected; low threshold for repeat imaging if clinical deterioration 3
• Supportive care: IV fluids and electrolyte replacement, blood transfusion to maintain hemoglobin >10g/dl, subcutaneous heparin for thromboprophylaxis 3, 9
• Nutritional support: Enteral or parenteral if malnourished 3

Patients should be informed of 25-30% colectomy risk, and surgical consultation should occur on admission 3.

Steroid-Refractory or Steroid-Dependent Disease

For patients failing to respond to IV steroids within 3-5 days or those requiring repeated steroid courses, second-line options include anti-TNF therapy (infliximab), vedolizumab, or thiopurines (azathioprine 1.5-2.5mg/kg/day or mercaptopurine 0.75-1.5mg/kg/day) 3, 9, 8:

• Infliximab is commonly used for steroid-refractory severe colitis 3
• Vedolizumab provides gut-selective immunosuppression 3
• Cyclosporine may be considered in specialist centers for severe steroid-refractory disease 3

Maintenance Therapy

Lifelong maintenance therapy is generally recommended for all UC patients, particularly those with left-sided or extensive disease 3, 9:

• Aminosalicylates are first-line maintenance agents 3, 9
• Thiopurines or biologic agents for steroid-dependent disease 3, 9
• Maintenance therapy may reduce colorectal cancer risk 3

Crohn's Disease of the Colon

Treatment depends on disease location (ileal, ileocolonic, colonic), pattern (inflammatory, stricturing, fistulating), and activity 3:

Mild Ileocolonic Disease

• High-dose mesalazine 4g daily may be sufficient 3

Moderate to Severe Disease

• Oral prednisolone 40mg daily with gradual taper over 8 weeks 3
• Budesonide 9mg daily for isolated ileocecal disease (marginally less effective than prednisolone) 3

Severe Disease

• Intravenous steroids (hydrocortisone 400mg/day or methylprednisolone 60mg/day) 3
• Concomitant IV metronidazole often advisable to distinguish active disease from septic complications 3

Microscopic Colitis (Collagenous and Lymphocytic)

Budesonide or high-dose bismuth preparations are effective first-line therapies for microscopic colitis causing chronic watery diarrhea 4:

• Both subtypes respond to similar treatments 4, 5
• Approximately 60% of lymphocytic colitis patients may have single attack 4
• Consider drug-induced causes and celiac disease association 4

Immunotherapy-Related Colitis

For grade 2 or higher diarrhea/colitis from immune checkpoint inhibitors, corticosteroids are first-line treatment 3:

Grade 1 (Mild)

• Hydration, consider holding immunotherapy, monitor closely 3
• Loperamide may be used cautiously 3
• Check fecal lactoferrin; if positive, treat as grade 2 3

Grade 2 or Higher (Moderate to Severe)

• Corticosteroids as first-line 3
• Infliximab for steroid-refractory cases 3
• Vedolizumab provides gut-selective alternative 3
• Introduction of infliximab or vedolizumab within 10 days of onset reduces symptom duration 3

Infectious Colitis

Mild infectious gastroenteritis requires only oral hydration; antimicrobial therapy is reserved for C. difficile, severe bacterial infections, travel-related diarrhea, and parasitic infections 6:

• Multiplex antimicrobial testing preferred over traditional stool cultures 6
• Empirical vancomycin for suspected C. difficile until toxin confirmed negative 3

Special Considerations

Colitis with Constipation

Proximal constipation in distal colitis should be treated with stool bulking agents or laxatives to improve drug delivery and symptom control 7, 8:

• Abdominal X-ray can identify fecal loading 3
• Continue laxative therapy alongside anti-inflammatory treatment 8

Toxic Megacolon

Toxic megacolon (colonic dilatation ≥5.5cm with systemic toxicity) requires immediate surgical consultation, IV hydrocortisone, and empirical oral vancomycin until C. difficile excluded 3:

• Risk factors include hypokalemia, hypomagnesemia, and antidiarrheal use 3
• Limited window for medical therapy before colectomy necessary 3

Critical Pitfalls to Avoid

• Never delay corticosteroid treatment in acute severe colitis while awaiting stool microbiology results 3
• Avoid antidiarrheal medications in active colitis as they mask worsening symptoms and may precipitate toxic megacolon 7, 9, 8
• Do not use rapid steroid tapers (faster than 8 weeks) as this increases relapse risk 3, 7, 8
• Always exclude infection before escalating immunosuppressive therapy 7, 8
• Ensure adequate aminosalicylate dosing (at least 2g daily for active disease) before declaring treatment failure 7
• Avoid long-term corticosteroid use due to significant side effects; transition to steroid-sparing agents 7, 9
• Recognize that topical mesalazine is more effective than topical corticosteroids for distal disease 3, 7
• Combination therapy (oral plus topical) is superior to monotherapy for distal and left-sided colitis 7, 9