April 19, 2022

Gastrointestinal (GI) bleeding is a common clinical problem encountered by clinicians in both the inpatient and outpatient settings. Evaluating bleeding that occurs in the upper and lower GI tract can be relatively straightforward, but bleeding from the small bowel can sometimes be more challenging.

In a review article published in Mayo Clinic Proceedings in 2022, Cadman L. Leggett, M.D., and co-authors discuss the differential diagnosis, diagnostic and therapeutic modalities, and clinical approach to small bowel bleeding. Dr. Leggett is a gastroenterologist at Mayo Clinic in Rochester, Minnesota, with expertise in the diagnosis and endoscopic management of gastrointestinal bleeding. In addition to contributing to the 2022 publication, Dr. Leggett co-authored a concise review for physicians on upper gastrointestinal bleeding that was published in Mayo Clinic Proceedings in 2019.

Classification, key terms and common causes

Dr. Leggett and co-authors note that there are three main terms related to the types of GI bleeding that clinicians should recognize and understand:

• Overt GI bleeding refers to bleeding that is visible, including bright red blood or by-products of blood breakdown in the emesis or feces.
• Occult GI bleeding refers to instances in which bleeding is suspected despite the lack of visual evidence, when iron deficiency anemia, fecal occult blood test positivity or both are confirmed.
• Small bowel bleeding (previously known as obscure GI bleeding) refers to instances in which evaluation for overt or occult GI bleeding with esophagogastroduodenoscopy (EGD) and colonoscopy does not identify a source of bleeding.

The researchers note that patient age and comorbidities should be considered when trying to determine the etiology of small bowel bleeding. For individuals younger than age 40, inflammatory bowel disease and Meckel's diverticulum are diagnoses to consider. For individuals 40 and older, vascular lesions such as angioectasias and nonsteroidal anti-inflammatory drug-induced ulceration and enteropathy are more common. Eroding submucosal blood vessels (Dieulafoy's lesions) and neoplastic lesions may be present in both age groups.

"Management of presumed small bowel bleeding should begin with an assessment of the hemodynamic stability of the patient," explains Dr. Leggett.

Algorithm for evaluating small bowel bleeding

Patients with brisk small bowel bleeding often require intensive care and examination using tools such as angiography that can yield results quickly. Management of occult or stable overt small bowel bleeding in patients who are hemodynamically stable can usually take place in the outpatient setting. Dr. Leggett and co-authors provide a detailed algorithm that can serve as a stepwise guide for clinicians to use when diagnosing and managing this condition.

The authors acknowledge that this practical algorithm is meant to serve as a guide and that the evaluation of small bowel bleeding should be tailored to each individual presentation.

For more information

Havlichek DH III, et al. A practical guide to the evaluation of small bowel bleeding. Mayo Clinic Proceedings. 2022;1:146.

Kamboj, AK, et al. Upper gastrointestinal bleeding: Etiologies and management. Mayo Clinic Proceedings. 2019;4:697.

Refer a patient to Mayo Clinic.