Prevention of Progression of Duodenal Adenomas in Patients With Familial Adenomatous Polyposis

Inclusion Criteria:

• Patients with Familial adenomatous Polyposis: APC-mutation identified or more than 100colorectal polyps on diagnosis

• Spigelman score of duodenal adenoma equal to II or III

Exclusion Criteria:

• Incapability of signing informed consent

• Active gastric or duodenal ulcer, gastrointestinal bleeding

• Cardiovascular disease or risk:

• Congestive cardiac failure: NYHA class II to IV

• Proven ischemic heart disease and/or cerebrovascular disease

• Risk factors: hypertension, hyperlipidaemia, diabetes mellitus, family history ofcardiovascular events (≥2 first degree family members <55 years)

• Renal dysfunction: creatinine clearance below 50mL/min

• Liver dysfunction: albumin below 25 g/L or Child-Pugh-score equal to or below 10

• Known allergic reaction to sulfonamides, NSAIDs or ursodeoxycholic acid

• Use of NSAIDs or ursodeoxycholic acid for more than 1 week during the 6 months priorto the start of the study

• Use of lithium

• Symptomatic gallstones

• Inflammatory bowel disease

• (Possible) pregnancy or breast feeding