Step "s" stands for:
identifying the problem
listing choices
judging whether or not your choice is right
developing a plan of action

The answer is: identifying the problem

During this stage, we need to observe the situation that we had at hand and try to analyze what cause it. Only After we get this part done, we can formulate the proper planning that can be executed to tackle the problem and improve our situation.

answer; eat a strict gluten-free diet;