GI bleeding

Initial considerations

• In the acutely bleeding patient, assessment and data collection must occur simultaneously with stabilization and initial management.
• All blood or blood-like material passed from the rectum should be tested initially to confirm that it is, in fact, blood.
• Previous ingestion of cherry or strawberry candies, Popsicles®, and medications containing bismuth salts can mimic the appearance of blood.

First steps in workup
 

• determining the level of the hemorrhage is essential.
• after stabilizing the patient, the first diagnostic procedure in any type of gastrointestinal bleeding should be passage of a nasogastric tube.
• The presence of esophageal varices is not a contraindication to the passage of this tube.

Determining where the bleed is from

• Blood losses from the upper gastrointestinal tract are more severe than from the lower gastrointestinal tract.
• Normally, upper gastrointestinal tract bleeding is associated with dark tarry stools (melena).
• However, bright red rectal bleeding may be of upper gastrointestinal origin in infants who have rapid intestinal transit (hematochezia) and in older children who have major gastrointestinal hemorrhage.
• The presence of borborygmi (the result of intestinal irritation by intraluminal blood) and an elevated serum blood urea nitrogen concentration (the result of reabsorbed nitrogen from the gastrointestinal tract) in these patients may suggest an upper gastrointestinal source of bleeding.
• Nasogastric aspirate that contains blood = lesion proximal to the ligament of Treitz in up to 90% of cases.
• small amounts of blood in the aspirate from the nasogastric tube may be difficult to interpret.
• If the blood clears rapidly from the tubing and does not reaccumulate, it is likely the result of trauma due to tube passage.
• If fresh blood is identified, aspiration of the gastric contents can be completed before upper endoscopy is performed.
• Upper endoscopy will localize the site of bleeding in more than 90% of such patients.
• If the nasogastric return is clear or bilious, the source of bleeding is not in the nasopharynx, esophagus, stomach, or proximal duodenum, and the nasogastric tube can be removed. 

Common causes of upper gastrointestinal bleeding in an adolescent include:

• duodenal or gastric ulcer
• esophagitis
• esophageal varices
• gastritis
• Mallory-Weiss tear.

Abdominal ultrasonography will not identify the mucosal abnormalities that result in bleeding. However, it will identify splenomegaly as a reflection of increased portal pressure and the possibility of esophageal varices as a cause of hemorrhage. Emergent colonoscopy and a Meckel scan are not helpful in the evaluation of upper gastrointestinal bleeding, which is the most likely site of the bleeding for the adolescent described in the vignette. Contrast studies of the upper gastrointestinal tract, which are particularly useful in identifying anatomic defects, often fail to identify mucosal abnormalities and have taken a secondary role in the evaluation of patients who have upper gastrointestinal hemorrhage.

Lower GI Bleeding

• Causes in newborn (birth to 1 month):
  • Swallowed maternal blood (diagnose with Apt test: based on different responses of adult and fetal hemoglobin; pink solution implies fetal, yellow-brown implies adult.)
  • Surgical: NEC, malrotation with volvulus
  • Neurologic: Hirschsprung disease
  • Hematologic: coagulopathy
  • Allergic: allergic colitis, milk-protein allergy
• Causes in infants (1 month to 2 years):
  • Neurologic: Hirschsprung disease
  • Surgical: intussusception (3mon to 3yrs)
  • Anatomic: anal fissure, Meckel’s diverticulum, intestinal duplication, lymphonodular hyperplasia
  • Allergic: allergic colitis,
  • Infectious: infectious colitis
  • Syndrome: Wiscott-Aldrich
• Causes in pre-school children (2 to 5 years):
  • juvenile polyp, infectious colitis, Meckel’s diverticulum, HSP, HUS
• Causes in school-age children (>5 years): IBD, infectious colitis, juvenile polyp
  
   

References:
Menzoff AG, Preud'Homme DL. How serious is that GI bleed? Contemp
Pediatr. 1994;11:60-92
Vinton NE. Gastrointestinal bleeding in infancy and childhood.
Gastroenterol Clin North Am. 1994;23:93-122
Wilcox CM, Alexander LN, Cotsonis G. A prospective characterization of
upper gastrointestinal hemorrhage presenting with hematochezia. Am J
Gastroenterol. 1997;92:231-235