Hi there, as your gastroenterologist has rightly pointed out it may be something to do with your diet and not able to move your bowel regularly.Common causes of constipation
are low roughage diet which means you are consuming more of refined food products or out of the box products andless of fruits and vegetables. Another cause is low water intake and a sedentary life style. You need to include more of fruits and vegetables in your diet along with at least 2 liters of water a day which is roughly 8 glasses. Start some kind of excersise like walking or yoga
. These minor changes in the lifestyle may relieve you if not then it would be worthwhile not to neglect it and get yourself further investigated. Take care!