Pouchitis in ileal anal anastomosis represents an important clinical complication after restorative proctocolectomy. Acute and chronic inflammation of the reservoir is a frequent event sometimes associated with villous atrophy and colonic metaplasia. After ileal pouch anastomosis, twenty-one patients affected by ulcerative colitis were studied. An image analyzer CAS 200 (Becton Dickinson) was utilized to evaluate the DNA intranuclear content in every biopsy. In two cases abnormal DNA distribution was observed, and in one case a poliploid pattern was seen. Abnormal DNA distribution was also present in colonic metaplasia. Therefore, image analysis for the detection of DNA aneuploidy may be of additional value together with histologic parameters in follow up, in order to exclude transformation of the ileal mucosa in neoplastic epithelia.