Hi tell him to try eating several small meals instead of three large ones whenever you can.Avoid foods that irritate his stomach, especially those that are spicy, acidic, fried or fatty.avoid coffee,tea etc.Stress may make his gastritis symptoms worse. Stress may be hard to avoid, but he can learn to cope with it. If he has trouble relaxing, consider calming activities, such as meditation, yoga etc...tell him to sleep with head raised position and  have dinner atleast 2 hours before sleep..consult doctor for specific treatment