Make sure you are drinking enough water or liquids. If water is hard to drink try crystal light lemonade. Make sure you are at least walking every day if not exercising. Also make sure if you are eating it is the majority of protein in your diet, and definitely don’t go over your calorie restriction. My group of buddies was told to intake 60 grams of protein a day.
The only other thing is you can become “backed up” even though you have not been eating a lot. So, miralax or the generic is what doctors recommend, just to follow the directions.
Hope that helps! Good luck.