What is the initial treatment approach for a patient presenting with colitis, specifically inflammatory bowel disease (IBD) such as ulcerative colitis or Crohn's disease?

Treatment of Colitis (Inflammatory Bowel Disease)

For newly diagnosed ulcerative colitis, start with high-dose oral aminosalicylates (4-4.8 g daily of active 5-ASA) combined with topical mesalazine (1 g daily) for distal or left-sided disease, escalating to oral prednisolone 40 mg daily if inadequate response within 2-4 weeks. 1

Initial Assessment and Severity Stratification

Before initiating treatment, determine disease extent (proctitis, left-sided, or extensive colitis) and severity (mild, moderate, or severe) through colonoscopy with biopsies. 1 Always rule out infectious causes first—obtain stool cultures for bacterial pathogens, C. difficile toxin, and consider CMV testing in severe cases, as superimposed infections account for a significant proportion of flares. 2

Use biomarkers to guide treatment intensity: fecal calprotectin >150 mg/g, elevated fecal lactoferrin, or elevated CRP reliably indicate moderate to severe endoscopic inflammation requiring more aggressive therapy. 2

Ulcerative Colitis Treatment Algorithm

Mild to Moderate Disease

First-line therapy:

• Distal colitis (proctitis): Topical mesalazine 1 g daily PLUS oral mesalazine 2-4 g daily—combination therapy is superior to either agent alone. 1
• Left-sided or extensive disease: Oral mesalazine 4-4.8 g daily PLUS topical mesalazine 1 g daily. 1
• Topical corticosteroids are less effective than topical mesalazine and should be reserved as second-line therapy. 1

If aminosalicylates fail or prompt response is required:

• Initiate prednisolone 40 mg daily, tapering gradually over 8 weeks according to severity and patient response—more rapid reduction is associated with early relapse. 3, 1

Severe Acute Colitis

Hospitalization is mandatory. 2 Severe colitis requires joint management by gastroenterology and colorectal surgery from the outset. 3

Immediate management:

• Intravenous corticosteroids: hydrocortisone 400 mg/day or methylprednisolone 60 mg/day. 3, 2
• Supportive care: IV fluid and electrolyte replacement, subcutaneous heparin for thromboprophylaxis, nutritional support if malnourished. 2
• Monitor vital signs four times daily, stool charts documenting number/character/blood. 2
• Laboratory studies every 24-48 hours: CBC, ESR or CRP, electrolytes, albumin, liver function tests. 2
• Plain abdominal X-ray to assess for colonic dilatation. 2

Rescue therapy if inadequate response after 3-5 days:

• Infliximab 5 mg/kg OR cyclosporine as rescue therapy. 2
• Patients should be kept informed of a 25-30% chance of needing colectomy during severe flare. 3, 2

Surgical indications:

• Failure of medical rescue therapy after 3-5 days. 2
• Toxic megacolon with clinical deterioration after 24-48 hours of medical treatment. 3
• Life-threatening bleeding with persistent hemodynamic instability. 3
• Free perforation with pneumoperitoneum and peritoneal fluid. 3
• Subtotal colectomy with ileostomy is the emergency operation of choice. 4

Crohn's Disease Treatment Algorithm

Mild Ileocolonic Disease

First-line therapy:

• High-dose mesalazine 4 g daily for mild ileal or ileocolonic Crohn's disease. 3, 1
• For less severe symptoms with ileocaecal location, ileal-release budesonide 9 mg daily may be tried initially, though marginally less effective than prednisolone. 3, 1

Moderate to Severe Disease

Systemic corticosteroids remain effective initial therapy:

• Oral prednisolone 40 mg daily for moderate to severe disease, tapered gradually over 8 weeks. 3, 1
• Intravenous steroids (hydrocortisone 400 mg/day or methylprednisolone 60 mg/day) for severe disease. 3
• Concomitant intravenous metronidazole is often advisable to distinguish between active disease and septic complications. 3

Alternative therapies for selected patients:

• Elemental or polymeric diets are less effective than corticosteroids but may be used in patients with contraindications to steroids or those preferring to avoid such therapy. 3
• Infliximab 5 mg/kg is effective but best avoided in patients with obstructive symptoms. 3

Surgical Indications

• Symptomatic intestinal strictures not responding to medical therapy and not amenable to endoscopic dilatation. 3
• Small bowel obstruction due to fibrotic or medically-resistant stenosis. 3
• Life-threatening bleeding with hemodynamic instability. 3
• Free perforation with pneumoperitoneum and peritoneal fluid. 3

Maintenance Therapy

Corticosteroids are NOT effective for maintaining remission and should not be used long-term. 1

For chronic active steroid-dependent disease:

• Azathioprine 1.5-2.5 mg/kg/day OR mercaptopurine 0.75-1.5 mg/kg/day as steroid-sparing agents. 3, 1
• These agents have slow onset of action (3-4 months) and should be started early as adjunctive therapy. 3

For ulcerative colitis in remission:

• Maintenance therapy with aminosalicylates reduces relapse risk and may reduce colorectal cancer risk. 3
• Discontinuation may be reasonable for distal disease in remission for 2 years in patients averse to medication, though this increases relapse risk. 3

Critical Pitfalls to Avoid

• Never delay surgery in critically ill patients with toxic megacolon—deterioration after 24-48 hours of medical treatment mandates surgery. 3
• Do not use corticosteroids for maintenance therapy—they are ineffective for maintaining remission and cause significant long-term toxicity. 1
• Always assess colorectal strictures with endoscopic biopsies to exclude malignancy before attributing symptoms to IBD. 3
• In hemodynamically unstable patients with free perforation and generalized peritonitis or toxic megacolon, use an open surgical approach rather than laparoscopic. 3
• Avoid attempting primary anastomosis in patients with 2 or more risk factors for anastomotic complications—perform subtotal colectomy with ileostomy instead. 4