In order to assess the effectiveness and potential limitations of continuous enteral nutrition (CEN) to correct denutrition related to underlying digestive diseases, 10 nutritional criteria were measured weekly in 92 under-nourished patients fed with CEN for a 3-7 week period. All the patients received a standard non-elemental diet providing a mean daily energy intake of 52.8 kcal/kg BW (36.5 kcal/kg BW by tube feeding and 16.3 kcal/kg BW orally). The influence of preexisting intestinal malabsorption, hypercatabolic status, and post-radiation or inflammatory bowel disease was studied by an a posteriori classification of patients in one of the six following groups: I (no limiting factor), II (malabsorption), III (catabolic disease), IV (catabolic disease and malabsorption), V (colitis), VI (enteritis). During CEN, 8 patients had transient and one had persistent vomiting while 3 developed bronchopneumonia. Gains in body weight, triceps skinfold, midarm muscle circumference, creatinine-height index, urinary sodium and serum transferrin were significant as early as the 2nd week of CEN. Serum albumin and cholesterol, hemoglobin, and total count of lymphocytes were not significantly affected. Sixty-five patients (71 per cent) had an objective nutritional improvement and mean spontaneous oral intake increased from 17.8 to 28.7 kcal/kg BW per day. Significant increase of oral intake and objective nutritional improvement were observed in each group, but a longer period of CEN was necessary to achieve this result in groups II, IV and VI.(ABSTRACT TRUNCATED AT 250 WORDS)