Case #286 – October, 2010
A 21-year-old man attending a local music festival developed intermittent diarrhea and abdominal cramps on the second day. He went to his health care provider who requested a stool specimen for routine testing. Figures A–E show what was observed on a wet mount prepared from a formalin-ethyl acetate (FEA) concentration at 1000x oil magnification. The objects in Figures A and B measured 30 micrometers on average in length; the objects in Figures C–E measured 20 micrometers on average in length. What is your diagnosis? Based on what criteria?

Figure A

Figure B

Figure C

Figure D

Figure E
Images presented in the DPDx case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.