Editor,—We read with interest the recent clinical @lert commentary by Rutgreerts ((2001) Gut 48:452–53; OpenUrlCrossRefPubMedWeb of Science) analysing the recently published study by Lochs and colleagues.1 Lochset al concluded that compared with placebo, 18 months of treatment with high dose Pentasa (mesalazine 4 g/day) made no difference to postoperative recurrence rates in patients with Crohn's disease involving the small intestine and colon or colon alone (26.3% v 25.6% for mesalazine and placebo, respectively). We feel that the study raises many new questions with regards to the role of 5-aminosalicylate (5-ASA) formulations in the …