Hello dear
Warm  welcome to Healthcaremagic.com
I have evaluated your query in details  .
*  Suggestions for hard bowel movements ( which usually separate issue 
    than protein shake intake )
-  Drink plenty of liquids .
-  High fiber diet with plenty of green leafy veg , whole grains  , cereals ,
   pulses , organic fresh fruits , legumes .
-  Avoid oily , spicy , dairy fat , non veg stuffs .
-  Intake of bulk forming laxative as Ispaghula husk 3 - 4 teaspoonful at
    night with a glass of drinking lukewarm water .
-  Avoid 
smoking , alcohol consumption if doing .
Hope this  will help  to clear your doubt   .
Wishing you fine recovery .
Regards .