Patients after abdominal surgery will receive enteral nutrition for 2 days, if she/he can tolerate 30% of goal-dose EN, then she/he will be randomized to Gradual or immediate Goal-dose EN group at day 3. Patients in Gradual Goal-dose EN group will receive increased calories gradually by EN and will reach the 80% of target energy by EN at day 8 while patients in immediate Goal-dose EN group will receive 100% of target energy by EN at day 3 after abdominal surgery. Both groups will receive EN for 5 days except 80% of target energy delivered by oral feeding or patients are discharged from hospital, whichever arrives first. The primary and secondary outcomes will be collected.
Patients will be randomized to Gradual or immediate Goal-dose EN group at day 3 after abdominal surgery. Patients will receive Goal-dose EN gradually or immediately after abdominal surgery. Both groups will receive EN for 5 days except 80% of target energy delivered by oral feeding or patients are discharged from hospital. The primary and secondary outcomes will be collected.