Abstract :
Background: Occult bleeding from the gastrointestinal tract is believed to be the most common cause
of iron-deficiency anemia (IDA) in patients without an obvious source of blood loss. In general, when a clinician sees a patient with IDA, a fecal occult blood test (FOBT) is sent. If it is positive, the patient will be recommended to undergo esophago-gastro-duodenoscopy (EGD), colonoscopy will be done also if EGD is negative. There are a few studies exploring the usefulness of this practice. This study was conducted to assess the prevalence and the sites of the gastrointestinal lesions that may cause occult bleeding in IDA Thai patients, and also to assess the efficacy of two types of FOBT(immuno-based and guaiac-based) in detecting GI bleeding in this population.
Methods: During a 10 months period we prospectively studied 69 patients with iron-deficiency ane-
mia. We tested FOBT using guaiac-based randomly, then repeat it after 72-hour diet restriction, by using immunobased test. All underwent EGD Colonoscopy was performed in patients with a negative EGD. For patients with negative endoscopic studies, small bowel study or capsule endoscopy were further studied.
Results: Fifty-one patients had a positive random guaiac-based FOBT. After diet restrictions, the posi-
tive results decreased to 28 positive tests. Immuno-based FOBT were positive in 20 patients. The agreement percentage between random and diet-restricted FOBT was 60.9%. Gastrointestinal endoscopy revealed at least one lesion that potentially responsible for blood loss in 12 of the 69 patients (17.4%). EGD revealed bleeding sources in 9 patients, and colonoscopy revealed in 4 patients. One patient had lesions in both upper and lower gastrointestinal tracts.
Conclusions: Among Thai IDA patients without obvious or active bleeding who were referred for further evaluation, the prevalence of gastrointestinal lesions is much lower than in the West. Upper gastrointestinal lesions are more readily identified. Although more specific, the immuno-based FOBT is less sensitive than the guaiac-based test.
[Thai J Gastroenterol 2006; 7(3): 126-131] |
file/Thai-Journal-of-gastroenterology-vol-7-no-3-2822335.pdf