Review article: aminosalicylates for distal colitis.

About two-thirds of patients with ulcerative colitis have an inflammatory involvement distal to the splenic flexure and therefore may be effectively treated with topical treatment. This allows the delivery of the active drug directly to the site of inflammation, limiting the systemic absorption and the potential side effects. Topical aminosalicylate therapy is the most effective approach, provided that the formulation reaches the upper extent of the disease. Suppositories should be considered the treatment of choice for proctitis and distal sigmoiditis. A 1 g Pentasa-suppository once daily induces a quicker clinical and endoscopic remission and was better tolerated than a 500-mg suppository twice daily. Enemas, foams and gel, thanks to their proximal spread, should be the treatment of choice for proctosigmoiditis and left-sided colitis. Oral aminosalicylates are less effective than topical therapies for patients with active disease; however, a combination of oral and topical aminosalicylates can be successfully tried in refractory patients. Topical aminosalicylates also play an important role in the maintenance of remission, and the combination of oral plus rectal 5-aminosalicylate is superior to the single agent. Patients who prefer not to continue on long-term rectal therapy can be treated with oral aminosalicylates.