It is the nature of research that answers often lead to more questions and the REB review element of research is no different.
 
An REB review is an iterative process between the PI and the REB which continues until such time as all elements have been satisfactorily addressed.
 
In the course of review, information provided by the study team may result in requests from the REB:
a) to modify elements of the study
b) for more information
 
At the conclusion of the review, the REB will provide one of the following decisions concerning the study:
a) Approved
b) Not Approved
c) Approval Not Required
 
Please see the link http://intranet.uhnresearch.ca/service/understanding-review-process which describes the review process.