To assess the effect of the addition of enteral tube feeding with polymeric diets to the standard treatment of acute attacks of inflammatory bowel disease a total of 43 patients admitted to hospital (23 with Crohn's disease and 20 with ulcerative colitis) were studied retrospectively. Total enteral nutrition was given to 26 as the sole nutritional supply and to 17 in conjunction with a normal ward diet, when appropriate, according to the severity of attack (control group). Nutritional state was assessed and classified in all patients at admission and at the end of the study, by measuring the triceps skinfold thickness, mid arm muscle circumference, and serum albumin concentration as representative of body fat, muscle protein, and visceral protein, respectively. At admission the three nutritional variables were not statistically different between the groups. There was a significantly positive effect on mid arm muscle circumference in patients on total enteral nutrition compared with the control group, but there was no effect on either triceps skinfold thickness or serum albumin concentration. The percentage of subjects requiring intravenous albumin infusion, however, was significantly less in the group fed enterally than in the control group. In addition, fewer patients in the group fed enterally required surgical treatment compared with the control group, despite the fact that one of the criteria for starting enteral nutritional support was the expectancy that surgery would be needed. Total enteral nutrition was well tolerated and no major side effects arose during its use in patients with acute exacerbations of inflammatory bowel disease.