At this posting, the CINAHL database is not retrieving correct results for your searches. For instance, a subject search for gastroenteritis results in articles not containing the term. EBSCO is aware of the problem and has made it their top priority.
If your CINAHL results are completely off-topic, please return to CINAHL at a later time and consider searching MEDLINE, which contains many of the citations that CINAHL does.
At the resolution of this problem, an update will appear in this post.
Update: The problem seems to have been resolved.