title: Prevalence of occult gastrointestinal bleeding in celiac disease.
abstract: OBJECTIVE
  By using colorimetric tests, reports have indicated that occult gastrointestinal bleeding is common in celiac disease. These results suggest that bleeding is a significant contributor to iron deficiency in this disorder and imply a significant inflammatory hemorrhagic component. Both these concepts are contrary to previous understanding of pathology of celiac disease. Furthermore, colorimetric tests provide an indirect and nonspecific assessment of blood loss. We therefore hypothesized that an accurate, quantitative, and specific method for blood loss, rather than a guaiac test, might give different findings. We report the results of stool blood loss measurement by using such a method.
  
  
  METHODS
  We measured stool blood loss directly by using 51Cr radiolabeled red cells in 18 consecutive patients with celiac disease who consented to the study, 12 with total villous atrophy and 6 with partial villous atrophy, before initiation of a gluten-free diet.
  
  
  RESULTS
  Average daily blood loss exceeded 1.5 mL in only 1 of 18 subjects. It is suspected, but unproven, that this subject had an alternate transient source of gastrointestinal bleeding.
  
  
  CONCLUSIONS
  Colorimetric tests give a high prevalence of positive results for occult gastrointestinal blood loss in celiac disease, whereas the more specific and direct radiochromium method gives a low prevalence. These results suggest that bleeding is uncommon in celiac disease, and that positive results with colorimetric tests might be due to excess loss of intestinal cells and/or malabsorption of peroxidase-containing foods. Our results suggest that bleeding is not an important contributor to the iron deficiency often found in these subjects.
authors.affiliation: Division of Hematology and Oncology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada. patty.wark@ualberta.ca
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mant
authors.forename: Vincent G
authors.initials: VG
authors.lastname: Bain
authors.forename: Conor G
authors.initials: CG
authors.lastname: Maguire
authors.forename: Keith
authors.initials: K
authors.lastname: Murland
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Yacyshyn
mesh_terms: D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000209:etiology; D001810:Blood Volume; D002446:Celiac Disease / Q000150:complications* / Q000473:pathology / Q000503:physiopathology; D002860:Chromium Radioisotopes; D003967:Diarrhea / Q000209:etiology; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D015995:Prevalence; D015431:Weight Loss
chemical_list: D002860:Chromium Radioisotopes