Background and Objectives: This study’s main aim was to observe the effects of a fibre-enriched nutrition solu- tion on requisite feeding volume, which is directly proportional to energy intake in mechanically ventilated pa- tients with enteral nutrition. Methods and Study Design: Some 120 patients who required mechanical ventila- tion and enteral nutrition with a nasogastric tube were studied. Upon ICU admission, the patient’s age, gender, weight, height, comorbidities, diagnosis and APACHE II score were recorded. We assigned two diets to the pa- tients randomly. The control group received the fibre-free nutrition solution. The study group, received the fibre- enriched nutrition solution. Prescribed feeding volume and administered feeding volume, gastric residual volume (GRV), volume ratio (VR), diarrhoea score and gastrointestinal complications (GIC) were recorded, along with daily biochemistry. Results: The two groups did not differ with respect to age, sex, weight, BMI, APACHE II score, target caloric intake or GRV (p>0.05). On days four and five, the study group had higher VR values (p<0.05). Seventy-one (59%) patients had at least one gastrointestinal complication; 44 (73%) of them were con- trols and 27 (45%) of them study patients. The most commonly observed GIC was diarrhoea. Thirty-eight pa- tients had diarrhoea in control group, and twenty-two patients had diarrhoea in study group, and this difference was statistically significant (p<0.001). There were no significant differences between the groups about vomiting and regurgitation. Conclusions: We suggest that ICU staff initiate enteral nutrition with fibre-enriched formulas rather than fibre-free formulas to avoid frequent feeding interruptions that cause protein energy malnutrition in ICU patients.