• Clinical science

Gastrointestinal bleeding


Gastrointestinal bleeding is categorized as either upper or lower bleeding, with the ligament of Treitz serving as an anatomical landmark to differentiate between the two. In approx. 70–80% of cases, the source of bleeding is localized in the esophagus, stomach, or duodenum (upper gastrointestinal bleeding, or UGIB). Lower gastrointestinal bleeding (LGIB) may occur in the colon, jejunum, and, in rare cases, the ileum. Although gastric and duodenal ulcers are frequently the cause, angiodysplasia, inflammatory diseases, and carcinomas may also contribute to gastrointestinal bleeding. Depending on the source of the bleeding and how long the blood remains in the digestive tract, clinical symptoms may include vomiting blood (hematemesis), black, tarry stool (melena), and fresh blood in stools (hematochezia).

Hospitalization is essential to monitor for signs of hemodynamic instability and shock caused by anemia and blood loss, which require swift intervention. The source of bleeding can often be located and treated simultaneously during endoscopy with injection therapy (e.g., epinephrine, sclerosants, fibrin glue) or ligation.


Etiology of upper and lower gastrointestinal bleeding

Upper gastrointestinal bleeding Lower gastrointestinal bleeding
Erosive or inflammatory
Traumatic or iatrogenic
  • Mallory-Weiss syndrome
  • Following endoscopic intervention/polypectomy
  • Following interventions such as polypectomy or biopsy
  • Post-surgery anastomotic bleeding


Clinical features

Clinical features of gastrointestinal bleeding
  • Melena (black, tarry stool)
  • Hematemesis
  • Hematochezia: indicates brisk bleeding; may cause severe blood loss with hemodynamic instability
  • Hematochezia
  • Melena
  • Colonic bleeding (maroon, jelly-like traces of blood in stools)
  • Rectal bleeding (streaks of fresh blood on stools)

Melena may be caused by upper as well as lower gastrointestinal blood loss! Bleeding of the mouth and throat (nocturnal nosebleeds, tumors) should also be considered as a possible cause!


Lower gastrointestinal bleeding

  • Occult bleeding or hemodynamically stable hematocheziacolonoscopy→ if negative, perform esophagogastroduodenoscopy (EGD)
  • Melena (more common with a UGI source of bleeding) → EGD → if negative, perform colonoscopy
  • Hemodynamically unstable hematochezia
  • If EGD and colonoscopy fail to locate the bleeding → evaluate small bowel bleeding or consider angiography for vascular etiologies (e.g., angiodysplasia)

Upper gastrointestinal bleeding

  • Hematemesis or melenaEGD → if negative, perform colonoscopy
  • Nasogastric tube aspiration
    • Can be considered if suspicion of UGIB is only low to moderate
    • Bright red blood or coffee-ground material is indicative of UGI source
  • If EGD and colonoscopy fail to locate the bleeding → evaluate small bowel bleeding

Small bowel bleeding

There is no one test that can be recommended, as it depends entirely on the circumstances.



Conservative treatment

  • General support: nasal cannula oxygen supplementation, IV substitution of fluids (no oral intake of food or fluids)
  • Consider elective intubation in patients with altered mental or respiratory state and severe, ongoing hematemesis
  • IV proton pump inhibitors
  • Prepare for blood transfusion (typing and cross-matching)

Interventional treatment

  • Emergency EGD; : in the event of significant bleeding
    • Injection therapy (epinephrine), sclerotherapy, ligation, or thermal coagulation may be used to treat an identified source of bleeding.
    • Bleeding polyp (e.g., in the colon) → polypectomy
    • If present, see treatment of esophageal variceal hemorrhage.
  • Angiography: vasoconstriction via vasopressin
  • Surgery (laparotomy): if bleeding cannot be contained through endoscopic intervention (rarely the case)

If there is any suspicion of gastrointestinal bleeding, two large caliber peripheral venous catheters should be inserted and preparations made for a possible blood transfusion!


We list the most important complications. The selection is not exhaustive.