Commentary

The main disadvantage of surgery for Crohn's disease is postoperative recurrence of disease even when all macroscopically involved bowel is removed. Risk factors for early recurrence are ileal or ileocolonic resection with ileocolonic anastomosis, heavy smoking, especially in females, and perforating type of disease. Within weeks to months after resection, new lesions can be visualised endoscopically just proximal to the ileocolonic anastomosis that will later evolve to full blown Crohn's disease. The placebo group in controlled recurrence prevention trials yielded symptomatic recurrence rates of about 20% at one year and 40% at two years. Subsequently there is a 10% increase in symptomatic recurrence per follow up year.

Strategies to prevent recurrence of Crohn's disease after ileocolonic resection have been largely unsuccessful to date. The current trial by Loch et al is the largest trial to date using a 5-aminosalicylic acid (5-ASA) formulation for prophylaxis of Crohn's recurrence. All patients entered the study within 10 days after resection and received a high dose (4 g) of the sustained 5-ASA release formulation Pentasa. The overall results show clearly that 5-ASA formulations are not effective in preventing symptomatic recurrence up to 18 months after surgery. The positive results in the subgroup of patients with Crohn's disease involving the small bowel only before resection is somewhat surprising. Does …