Morphologic and functional hepatic changes occur in inflammatory bowel disease (IBD). Patients with this disease often require the administration of artificial nutritional support. Liver function tests (LFT) derangement is a widely recognized side-effect of total parenteral nutrition (TPN). Therefore, the use of this modality of nutritional support may be an additional factor to cause hepatic damage in IBD patients. However whether or not the same occurs in patients receiving total enteral nutrition (TEN) is not well-established. The aim of the present study was to evaluate the effect of TEN upon LFT in patients with moderate to severe acute attacks of IBD, by means of a prospective, controlled, and nonrandomized design. Forty-nine patients were included; 29 (11 patients with ulcerative colitis and 18 with Crohn's disease) received TEN, and 20 (11 with ulcerative colitis and 9 with Crohn's disease) did not. Both groups were homogeneous regarding age, sex, disease activity index, nutritional status, and length of the study (24.8 +/- 1.3 vs 23.9 +/- 16.8 days). In all cases, weekly measurements of serum alkaline phosphatase, GOT, and GPT were performed. There were no significant differences in LFT at the beginning of the study between groups. The percentage of patients showing derangement of some LFT during the study did not differ between both groups: six of 29 (20.6%) in TEN group vs three of 20 (15%) in control group. Six out of the nine patients (in both groups) who developed LFT derangement had one or more causes, other than TEN for explaining hepatic dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)