Evaluation of a String Test in Nonbleeding Individuals

Abstract

Using the commercially available gastrointestinal string, type 2, we evaluated the string test without fluorescein in 15 volunteers who had no evidence of gastrointestinal tract disease or bleeding. Six subjects (40 %) had significant blood stains on the string using Smith's criteria. Such a large proportion of false positive results emphasizes the limited diagnostic usefulness of this variation of the string test.