Occult bleeding from the gastrointestinal (GI) lesions is a common cause of iron deficiency anemia (IDA). The information concerning the prevalence and the appropriate strategy of GI evaluation in Thai IDA patients is scant. The aim of this study is to prospectively evaluate Thai patients with IDA for GI lesions with bidirectional endoscopy.
One hundred and three consecutive patients with IDA were investigated by esophagogastroduodenoscopy (EGD) and colonoscopy. Any significant GI lesion was identified. Clinical data from history and physical examination and results of the fecal occult blood testing (FOBT) were collected to determine factors associated with the presence of GI lesions.
The age of the 103 patients was 63.6 ± 15.2 years. Significant GI lesions were detected in 58 patients (56%), 43% from EGD, 25% from colonoscopy. Twelve patients (12%) had dual lesions from both EGD and colonoscopy. The most common lesions were peptic ulcers (22%) and colonic carcinoma (13%). Anti-platelet used and positive FOBT were associated with significant GI lesions, with odds ratios of 2.37 (95% CI 1.05-5.36, p = 0.036) and 2.83 (95% CI 1.05-7.68, p = 0.038), respectively. The sensitivity, specificity, PPV and NPV of FOBT for significant GI lesions were 81%, 40%, 68% and 66%, respectively. Site-specific symptoms correctly guided the route of endoscopy in only half of the patients.
The prevalence of GI causes of IDA in Thai patients as evaluated by bidirectional endoscopy is 56%. Peptic ulcers and colorectal cancer are the two most common causes. EGD has a higher yield than colonoscopy, and is the preferred initial endoscopy unless there are suggestive lower GI symptoms. Dual lesions are common. Bidirectional endoscopy is required in most patients unless cancer is detected by the initial endoscopy.No factors, including FOBT, can reliably predict the presence of GI lesions.