What is the initial treatment approach for microscopic colitis?

Initial Treatment Approach for Microscopic Colitis

Budesonide is strongly recommended as the first-line treatment for induction of clinical remission in patients with symptomatic microscopic colitis, based on high-quality evidence. 1, 2

First-Line Treatment Algorithm

1. Identify and discontinue potential triggering medications

   • Consider discontinuation of NSAIDs, proton pump inhibitors (PPIs), and selective serotonin reuptake inhibitors (SSRIs) when clinically feasible 2, 3
   • Smoking cessation should be encouraged as smoking is a risk factor 4, 3

2. For mild symptoms:

   • Begin with antidiarrheal agents such as loperamide for immediate symptomatic relief 4, 3
   • These can be used as adjunctive therapy alongside other treatments 3

3. For moderate to severe symptoms:

   • Budesonide is the treatment of choice with strong recommendation and high-quality evidence 1, 2
   • Typical induction dosing is 9 mg daily for 8 weeks 2
   • Budesonide has demonstrated superior efficacy compared to other treatments and significantly improves quality of life 1, 2

4. If budesonide therapy is not feasible:

   • Mesalamine is suggested as an alternative (conditional recommendation, moderate quality evidence) 1, 2
   • Bismuth salicylate can be considered (conditional recommendation, low quality evidence) 1, 2
   • Prednisolone/prednisone may be used (conditional recommendation, very low quality evidence) 1, 2

Maintenance Therapy

• For patients who experience symptom recurrence after discontinuation of induction therapy, budesonide is strongly recommended for maintenance of clinical remission 1
• Maintenance therapy with budesonide 6 mg daily over 6 months reduces the risk of clinical relapse by 66% (relative risk 0.34,95% CI 0.19-0.6) 1
• In clinical practice, budesonide is commonly tapered to the lowest effective dose 1
• Maintenance therapy should be considered for 6-12 months before attempting discontinuation 1
• Up to one-third of patients may not require maintenance therapy 1

Treatment Considerations and Monitoring

• Despite low systemic bioavailability, prolonged use of budesonide may predispose to bone loss 1
• Osteoporosis prevention and screening should be considered in patients requiring maintenance therapy 1
• The goal of therapy is to reduce the number of bowel movements, improve stool consistency, and enhance quality of life 3, 5

Not Recommended Treatments

• Combination therapy with cholestyramine and mesalamine is not recommended over mesalamine alone 1, 2
• Boswellia serrata is not recommended 1, 2
• Probiotics are not recommended 1, 2

Management of Refractory Disease

• For patients with budesonide-refractory disease, re-evaluate for other causes of diarrhea, including celiac disease 2, 6
• Consider immunomodulators (response rates 0%-56%) or anti-TNF therapy (response rates 66%-100%) for truly refractory cases 7
• Multidisciplinary team discussion is recommended for management of refractory cases 6

Clinical Pearls

• Microscopic colitis is a common cause of chronic watery diarrhea, particularly in older women 4, 5
• The colon typically appears normal endoscopically, making histologic evaluation essential for diagnosis 4, 5
• The disease course is variable; some patients experience occasional symptoms while others have chronic or progressive symptoms 4
• Relapse rates are high (up to 82%) when budesonide is discontinued, necessitating careful monitoring 7