Have been successful with an H&E, also a Giemsa which is not destained
or differentiated too much.  It worked with both paraffin and GMA sections,
the latter the more spectacular, but not always feasible.  It may be a
good idea to try and inoculate a mouse, collect all the intestine as
a positive control, we did NBF fixation.  This helps identify the 
Cryptosporidia attached to villi in intestine. 

We also did not differentiate the hematoxylin, these tend to not stain
very well, just stained and blued the sections.

Gayle Callis