What is the treatment for descending and sigmoid colitis?

Treatment of Descending and Sigmoid Colitis

For descending and sigmoid colitis, the first-line treatment is a combination of oral and topical mesalazine therapy, with oral mesalazine 2-4g daily plus topical mesalazine 1g daily in the appropriate formulation for the extent of disease. 1

Treatment Algorithm Based on Disease Severity

Mild to Moderate Disease

• For left-sided colitis (including descending and sigmoid regions), use oral mesalazine 2-4g daily or balsalazide 6.75g daily as effective first-line therapy 1
• Combine oral therapy with topical mesalazine (enemas for descending colon involvement, suppositories for sigmoid/rectal disease) for better efficacy than either alone 1, 2
• Once-daily dosing with mesalazine is as effective as divided doses and may improve adherence 1
• Olsalazine 1.5-3g daily is an alternative but has higher incidence of diarrhea in extensive disease 1
• Sulphasalazine 2-4g daily is effective but has more side effects than newer 5-ASA drugs; may be beneficial for patients with reactive arthropathy 1, 3

Topical Therapy Considerations

• For sigmoid involvement, use mesalazine enemas rather than oral therapy alone 1
• Topical mesalazine is more effective than topical corticosteroids 1
• Topical corticosteroids should be reserved as second-line therapy for patients intolerant to topical mesalazine 1
• Choice of topical formulation should match disease extent: suppositories for rectosigmoid junction, foam or liquid enemas for more proximal disease 1

Inadequate Response to First-Line Therapy

• If no improvement with combination of oral and topical mesalazine, initiate oral prednisolone 40mg daily 1
• Topical agents may be used as adjunctive therapy with systemic corticosteroids 1
• Prednisolone should be tapered gradually over 8 weeks; more rapid reduction is associated with early relapse 1
• Long-term steroid treatment should be avoided due to significant side effects 2

Steroid-Dependent or Refractory Disease

• For chronic active steroid-dependent disease, use azathioprine 1.5-2.5 mg/kg/day or mercaptopurine 0.75-1.5 mg/kg/day 1, 2
• Cyclosporine may be effective for severe, steroid-refractory colitis 1

Special Considerations

Disease Confirmation and Monitoring

• Disease activity should be confirmed by sigmoidoscopy and infection excluded before initiating treatment 1
• Proximal constipation should be treated with stool bulking agents or laxatives 1, 2
• Avoid antidiarrheal medications as they can mask worsening symptoms while allowing underlying inflammation to progress 2

Maintenance Therapy

• Aminosalicylates are effective and safe for maintenance therapy 2, 4
• Controlled-release mesalamine at 4g/day has shown 64% 12-month remission rates compared to 38% for placebo 4
• Combination of oral and topical mesalazine therapy may be more effective for maintaining remission than oral therapy alone 5, 6

Common Pitfalls and Caveats

• Ensure adequate dosing of mesalazine (at least 2g daily for active disease) 1, 7
• Don't delay corticosteroid treatment if no response to optimized 5-ASA therapy 1
• Avoid long-term steroid use; transition to steroid-sparing agents if needed 2
• Monitor for side effects of medications, particularly with sulphasalazine which has higher incidence of adverse effects 3, 5
• Consider the increased risk of adverse outcomes with severe disease in elderly patients 2