Before administering an intermittent tube feeding through a nasogastric tube, the nurse checks for gastric residual volume. which is the best rationale for checking gastric residual volume before administering the tube feeding?

Evaluate absorption of the last feeding.

If the absorption of the last feeding is low you might suspect an obstruction. Checking gastric residual is also important because feeding with nasogastric tube has a risk to overfeed and might induce nausea and cause the patient to throw up. 

Were is the question