The detrimental effects of catabolism, insuline resistance and muscle wasting on surgical outcome is wellknown. This catabolism is especially pronounced in patients with acute or chronic inflammation (IBD, cancer) and for those undergoing major surgery. Patients with ulcerative colitis operated with an ileal pouch-anal anastomosis (j-pouch) fall well into both these categories.

To prevent this undesirable catabolism, we will investigate the effects of intravenous administration of predominantly anabolic amino acids (with an amino acid content equal to breast milk) on whole body metabolism, with special emphasis on muscle and fat metabolism and intracellular signalling pathways.

Twenty-four patients will be block-randomized by gender in this parallel-group, randomized, assessor-blinded, placebo-controlled trial to receive either Vaminolac® (Fresenius Kabi) or saline. Metabolism before and after the intervention will be assessed by palmitate- and amino acid kinetics of radioactively labelled tracers, while muscle and fat biopsies will be analyzed for differences in intracellular signaling pathways (PI3 kinase, Akt, etc.) as a measure of cellular activity.

With this study we hope to find evidence for anabolic effects of intravenous amino acids in j-pouch surgery for ulcerative colitis. The perspective is a potential for primary prophylaxis of surgical complications, reduction in the length of hospitalization, and subsequently optimized long-term functional outcome of the pouch.

Inclusion Criteria:

• Patients with ulcerative colitis who are having an ileal pouch-anal anastomosis performed, 18 < age < 50, written informed consent.

Exclusion Criteria:

• Inability to understand written Danish, postmenopause, severe asthma, diabetes mellitus, severe rheumatologic disease, severe comorbidity (ASA group III-IV) in general. Acute or progressing liver failure, uremia without possibility for dialysis, phenylketonuria, defects in amino acid metabolism. Participation in scientific studies in the preceding year, where ionizing radiation has been used, including significant x-ray investigations.