What is the treatment for colitis?

Treatment of Colitis

Treatment depends critically on the type and severity of colitis—ulcerative colitis requires a stepwise approach based on disease extent and severity, while immune checkpoint inhibitor colitis demands prompt recognition and glucocorticoid therapy.

Initial Assessment and Classification

Before initiating treatment, determine the specific type of colitis and exclude infectious causes:

• Exclude infectious etiologies first by obtaining stool cultures (including C. difficile, parasites, CMV) before starting immunosuppressive therapy 1, 2
• Measure inflammatory markers including fecal calprotectin or lactoferrin in patients with grade 2 or higher diarrhea (>4 bowel movements daily above baseline) to stratify risk 1
• Classify ulcerative colitis severity using clinical parameters: severe disease is defined by bloody stool frequency ≥6/day plus at least one of tachycardia >90/min, temperature >37.8°C, hemoglobin <10.5 g/dL, or ESR >30 mm/h 3, 2
• Obtain baseline labs including CBC, CMP, ESR/CRP, serum albumin, and liver function tests 1, 2

Treatment Algorithm for Ulcerative Colitis

Mild to Moderate Disease by Location

For proctitis (rectal involvement only):

• Start mesalazine 1g suppository once daily as first-line therapy 3

For left-sided or extensive colitis:

• Initiate oral mesalazine 2-4g daily combined with topical mesalazine 1g daily for superior efficacy compared to monotherapy 1, 3, 2
• Topical therapy should be retained if tolerated, though systematic studies in acute severe colitis are lacking 1

For moderate to severe disease:

• Start oral prednisolone 40-60mg daily combined with mesalazine 1, 3, 2
• Taper prednisolone gradually over 8 weeks according to severity and patient response—more rapid reduction increases early relapse risk 1

Acute Severe Colitis (Hospitalized Patients)

Immediate management requires:

• Intravenous methylprednisolone 40-60mg/24h or hydrocortisone 100mg four times daily—higher doses are no more effective, lower doses are less effective 1, 2
• Bolus injection is as effective as continuous infusion 1
• Assess response by day 3—in non-responders, consider salvage therapy with ciclosporin, infliximab, tacrolimus, or surgery 1
• Do not extend IV steroid therapy beyond 7-10 days as this carries no additional benefit 1

Essential supportive measures:

• IV fluid and electrolyte replacement to correct dehydration, with blood transfusion to maintain hemoglobin >8-10 g/dL 1
• Subcutaneous low-molecular-weight heparin for thromboembolism prophylaxis—risk is substantially elevated during disease flares 1, 3
• Nutritional support (enteral preferred over parenteral) if malnourished 1
• Withdraw anticholinergics, antidiarrheals, NSAIDs, and opioids which may precipitate colonic dilatation 1
• Daily abdominal examination and vital signs monitoring four times daily 1
• Daily abdominal radiography if colonic dilatation (transverse colon >5.5 cm) detected at presentation 1

Salvage Therapy for Steroid-Refractory Disease

When patients fail to respond to IV steroids by day 3:

• Ciclosporin 2mg/kg/day IV is effective and can be used as monotherapy in patients who should avoid steroids (steroid psychosis, osteoporosis, poorly controlled diabetes) 1
• Infliximab 5mg/kg IV at weeks 0,2, and 6 is equally effective as ciclosporin 1, 4
• Tacrolimus is an alternative calcineurin inhibitor option 1
• Recommend colectomy if no improvement after 4-7 days of salvage therapy—prolonged observation increases morbidity and mortality 1, 3, 5

Surgical Indications

Emergency surgery is indicated for:

• Failure to improve or deterioration within 48-72 hours of medical therapy initiation 3
• Toxic megacolon complicated by perforation, massive bleeding, clinical deterioration, or shock 3
• Free perforation, life-threatening hemorrhage, or generalized peritonitis 3
• Subtotal colectomy with ileostomy is the preferred surgical approach in emergency settings 3, 5

Treatment of Crohn's Disease Colitis

Active Ileocolonic/Colonic Disease

Mild disease:

• High-dose mesalazine 4g daily may be sufficient initial therapy 1

Moderate to severe disease:

• Oral prednisolone 40mg daily for patients failing mesalazine 1
• Reduce gradually over 8 weeks—more rapid reduction increases relapse risk 1
• Budesonide 9mg daily is appropriate for isolated ileocecal disease with moderate activity, though marginally less effective than prednisolone 1

Severe disease:

• IV hydrocortisone 400mg/day or methylprednisolone 60mg/day 1
• Concomitant IV metronidazole is often advisable 1

Treatment of Immune Checkpoint Inhibitor Colitis

For ICI-associated colitis:

• Exclude infectious causes before treatment 1
• Obtain endoscopic confirmation before initiating high-dose systemic glucocorticoids 1
• ICI colitis typically responds to high-dose systemic glucocorticoids 0.5-2mg/kg prednisone equivalent daily with 4-6 week taper 1
• Infliximab and vedolizumab are reasonable options for glucocorticoid-refractory colitis 1
• Budesonide is ineffective for prophylaxis but may treat ICI-associated microscopic colitis 1
• Permanently discontinue CTLA-4 agents for grade ≥2 colitis; may restart PD-1/PD-L1 agents if recovery to grade ≤1 2

Maintenance Therapy

Lifelong maintenance is recommended for all patients with ulcerative colitis:

• Continue the agent successful in achieving induction, except corticosteroids which must never be used for maintenance 3, 2, 6
• Options include mesalazine 2-4g daily, azathioprine/6-mercaptopurine (with therapeutic drug monitoring), or biologic therapy continuation 2
• Particularly critical for patients with left-sided or extensive disease 1, 3, 6
• Discontinuation may be reasonable only for distal disease patients in stable remission for ≥2 years who are averse to medication 1, 6

Advanced Therapy for Refractory Disease

For moderate-to-severe ulcerative colitis failing conventional therapy:

• Biologic options include infliximab, adalimumab, vedolizumab, ustekinumab, or tofacitinib 3
• For patients with prior infliximab exposure, prefer ustekinumab or tofacitinib over vedolizumab or adalimumab, particularly with primary non-response 3
• Switching out of class is reasonable when adequate drug concentration is achieved without response 3
• Screen for latent tuberculosis, hepatitis B, and HIV before initiating biologics 2

Treatment Goals

The treatment paradigm has shifted:

• Aim for biochemical, endoscopic, and histological remission—not just clinical response—to prevent long-term complications 3, 2
• Mucosal healing on endoscopy and/or fecal calprotectin ≤116 mg/g should guide treatment decisions 2

Critical Pitfalls to Avoid

• Never delay surgery in critically ill patients with toxic megacolon—this increases perforation risk with high mortality 3, 5
• Never use corticosteroids for long-term maintenance due to significant adverse effects 3, 2, 6
• Do not delay treatment with corticosteroids while awaiting stool microbiology results in acute severe colitis 1
• Do not extend IV steroid therapy beyond 7-10 days without considering salvage therapy or surgery 1
• Avoid prolonged observation in steroid-refractory patients—increases toxic megacolon and perforation risk 5
• Joint medical and surgical management is mandatory—maintain close liaison with a colorectal surgeon specializing in IBD 1