• All patients aged 18 years or older with Crohn's disease who undergo resection with an endoscopically accessible primary anastomosis which results in macroscopic normality.

• Patients having a reversal of a temporary ileostomy created after previous surgery for Crohn's disease may be enrolled provided that the reversal of the ileostomy results in a primary anastomosis and macroscopic normality of the remaining bowel.

• Patients with co-existing perianal disease may be included provided the resection has led to a primary anastomosis and macroscopic normality of the intestine.

• Patients must have proven history of Crohn's disease based on (clinical, radiologic, endoscopic and histologic criteria).