<<Disclaimer: Verify this information before applying it to your situation.>> My apologies for the delay in posting this! I had 14 helpful replies to my query,plus one that was definitely not helpful so I simply deleted it [guess that lister was having a bad day as it was the same person who sent the unhelpful reply to my other query.] The concensus is that occult [microscopic] blood is very common in people with CD, especially when one is having a reaction.Listers sent references to 3 articles/websites which were helpful: 1. http://www.celiac.com for the review of Dr. Fine's study of the issue 2. American Family Physicians: A New View of Occult and Obscure Gastrointestinal Bleeding http://aafp.org/afp/20040215/875.html 3. http://forums.delphiforums.com/celiac/start I can now relax about this part of my son's difficulties, at least! Thanks to everyone who responded! Cheers. Aggi-Rose *Support summarization of posts, reply to the SENDER not the Celiac List*