Analyze subset of data in table

[holmes123]

I have data as below. Patients can have several visits of various types. Some visit types may repeat (Initial Visit is the exception).

ID	Visit	        VisitDate       Other Variables (not shown)
------------------------------------------------------------
1	Initial Visit	1/1/2005
1	Check-Up	2/2/2005
1	Well-Being	3/10/2005
1	Well-Being	7/7/2005
1	Surgery	        9/1/2008
------------------------------------------------------------
2	Initial Visit	2/3/2000
2	Check-Up	5/1/2000
2	Well-Being	3/1/2001
------------------------------------------------------------
3	Initial Visit	7/1/2009
3	Surgery 	4/1/2010

I'm using Pivot Tables to analyze these data. How can I answer questions like:

1. Among patients who had Well-Being visits, how many had a Surgery visit? [The answer is 2 patients had Well-Being visits, 1 of whom has had a Surgery visit.]

2. What is the average number of days that passed between the Initial Visit and the Surgery Visit?

To answer questions like these via the pivot, I suspect I need to restructure the data somehow, but I'm not entirely sure of the best way of even if that's necessary.

Thank you for any suggestions.