An 82-year-old man is evaluated for recurrent obscure gastrointestinal bleeding. He has experienced four episodes of melena in the past 6 months. Results of a colonoscopy and upper endoscopy 3 months ago were unremarkable. There is no family history of bleeding diathesis. His only medication is iron sulfate for anemia.
On physical examination, vital signs are normal. BMI is 32. There is no abdominal tenderness. Digital rectal examination is normal.
Laboratory studies reveal a hemoglobin level of 10.1 g/dL (101 g/L); platelet count, complete metabolic panel, and INR are normal.
Which of the following is the most appropriate diagnostic test to perform next?
Answer & Critique(Correct Answer: B)
- Patients with suspected obscure gastrointestinal bleeding should undergo repeat colonoscopy and/or upper endoscopy (depending on the suspected site of bleeding), as approximately 30% to 50% of lesions can be detected using this approach.
Evaluate obscure gastrointestinal bleeding.
The next diagnostic step is to repeat the upper endoscopy. The sources of gastrointestinal bleeding may not be readily identified at the time of the initial endoscopy for various reasons. Lesions may bleed intermittently. Volume contraction or a low hemoglobin concentration may alter the appearance of a bleeding source. In a patient with recurrent bleeding, endoscopy and/or colonoscopy should be repeated. Endoscopy also allows for treatment of the lesion if one is found. Approximately 30% to 50% of lesions can be detected on repeat endoscopy. If a repeat study is nondiagnostic, the next step depends upon the severity and suspected location of blood loss.
Wireless capsule endoscopy, single-balloon enteroscopy, and intraoperative endoscopy are reserved for patients in whom repeat endoscopy does not identify a diagnosis. Intraoperative endoscopy is not usually required for diagnosis because wireless capsule endoscopy and double-balloon enteroscopy have improved the ability to diagnose and treat small-bowel sources of bleeding. Nevertheless, intraoperative endoscopy may be required for ongoing life-threatening bleeding without an identified source. Push single-balloon enteroscopy consists of direct insertion of an endoscope longer than the standard upper endoscope. Push enteroscopy is most often performed for the evaluation of lesions detected on capsule endoscopy that are within the reach of the enteroscope. In wireless capsule endoscopy, a patient swallows a video capsule that passes through the stomach and into the small intestine. The video capsule transmits images to a recording device worn by the patient. The images are downloaded onto a computer where they can be reviewed. Capsule endoscopy has been shown to detect sources of bleeding in 50% to 75% of patients and is considered the test of choice to follow standard endoscopy in patients with obscure bleeding.