What Causes Gastrointestinal (GI) Bleeding?

Blood in the stool or vomitus is typically of great concern to parents and physicians. Massive bleeding can be life threatening and must be treated rapidly to replenish the vascular compartment and stop the hemorrhage. In many other cases the quantity of blood lost is not so large as to be immediately dangerous. Table 61-1 lists the common causes of bleeding by age. Congenital lesions cause problems early in life, but some types of bleeding can occur at any age.

Table 61-1 Causes of Gastrointestinal Bleeding by Age

* Any cause of hematemesis can also present as rectal bleeding.

What Questions Help Assess GI Bleeding?

Table 61-2 Causes of Gastrointestinal Bleeding by Clinical Presentation

What Should I Look for on Physical Examination?

First, remember the ABCs (Chapter 31): Determine the hemodynamic status. Is the child pink, blue, or pale? Is there increased work of breathing? Are blood pressure and pulse rate appropriate for age, high, or low? Are pulses palpable and strong? Is capillary refill < 2 seconds or prolonged? Look for bruising and petechiae, which indicate possible coagulopathy. Signs of liver disease include hepatosplenomegaly, jaundice, and prominent abdominal veins. Evaluate the abdomen carefully for tenderness, distention, bowel sounds, and mass lesions. Location of tenderness may help identify the source of bleeding. For example, epigastric tenderness suggests peptic disease, whereas a tender mass in the right lower quadrant may indicate Crohn’s disease. Bowel obstruction such as volvulus or intussusception causes hyperactive, high-pitched “pinging” bowel sounds; distention; bilious emesis; and colicky pain. Always perform a rectal examination and test stool for blood, regardless of stool color.

What Laboratory Tests Should I Perform?

Table 61-3 lists suggested laboratory studies for children with GI bleeding. Remember that acute bleeding will not immediately cause a drop in the hemoglobin or hematocrit. You must select tests to rule out coagulopathy, identify liver disease, and assess hydration status, renal function, and electrolytes. When there is evidence of massive bleeding, send a specimen to the blood bank immediately!

Table 61-3 Laboratory Investigation of Gastrointestinal Bleeding

What Imaging Studies Should I Order?

Your clinical judgment is important at this point. Do not order every test available—focus on those studies that will best test your diagnostic hypothesis. In many cases, endoscopy is preferred to any other test. Table 61-2 lists imaging studies for the evaluation of different clinical presentations.

How Should I Begin Management of Gastrointestinal Bleeding?

Your initial evaluation determines possible sources of bleeding and the patient’s hemodynamic status. If the child has normal vital signs and a history of only minor blood loss, such as a few streaks of bright red blood in the stool, proceed directly to appropriate diagnostic tests. If bleeding is more severe, you must stabilize the patient and stop the bleeding. Figure 61-1 gives a suggested approach to management.

Figure 61-1 Initial therapy for gastrointestinal bleeding. BP, Blood pressure; bpm, beats per minute; CBC, complete blood count; ICU, intensive care unit.

When Should a Gastroenterologist Be Consulted?

Consulting a pediatric gastroenterologist is a high priority in all cases of significant GI bleeding, especially when you suspect a condition that can be treated directly through the endoscope, or when an accurate diagnosis is most likely to be achieved by direct visualization or biopsy. A gastroenterologist can usually stop the bleeding from esophageal varices, peptic ulcers, and arteriovenous malformations if they are within reach of the endoscope. Endoscopic biopsy can diagnose inflammatory bowel disease and other conditions, such as allergic colitis of infancy.

What Is Inflammatory Bowel Disease?

Inflammatory bowel disease (IBD) refers to disorders that cause chronic inflammation of the GI tract. Ulcerative colitis (UC) is characterized by continuous, chronic mucosal inflammation only in the colon, starting from the anus and extending proximally to a variable extent. Crohn’s disease (CD), on the other hand, is a chronic inflammatory disorder that may involve any part of the GI tract, from the mouth to the anus. UC and CD usually can be differentiated by the clinical features listed in Table 61-4.

Table 61-4 Differentiating Features of Ulcerative Colitis and Crohn’s Disease

What Are the Causes and Risk Factors for Inflammatory Bowel Disease?

The cause of IBD remains unknown. Genetic susceptibility and environmental influences both have a role in pathogenesis. The most important risk factor is family history: When close relatives are affected, risk of IBD in a symptomatic patient is in the range of 7% to 22%.

What Is the Differential Diagnosis of Inflammatory Bowel Disease?

Because IBD has a wide spectrum of clinical presentations, the differential diagnosis can be quite wide. Bacterial infections and parasitic infestations can mimic UC and Crohn’s colitis. Chronicity of symptoms and negative stool culture results favor IBD as opposed to infection. Abdominal pain has a very broad list of potential causes (see Chapter 17). Celiac disease can present with growth failure, anemia, abdominal pain, and nonbloody diarrhea.

In Which Patients Should I Suspect Inflammatory Bowel Disease?

IBD most often occurs in adolescents, but should be suspected in children with anemia, chronic abdominal pain, or failure to thrive, as well as those with more obvious symptoms such as bloody diarrhea and perianal fistulae. Symptoms of CD can be quite subtle, including short stature and delayed puberty in adolescents.

How Does Inflammatory Bowel Disease Typically Present?

IBD, particularly CD, has a wide variety of presentations, including extraintestinal manifestations (Table 61-5). These features may appear before, with, or after the onset of the GI symptoms. Growth failure is a prominent extraintestinal manifestation of CD.

Table 61-5 Extraintestinal Manifestations of Inflammatory Bowel Disease

What Should I Look for on Physical Examination?

Vital signs and hydration status should be assessed. Assessment of growth is essential: Children with small bowel CD often appear chronically ill because of growth failure, malnutrition, and anemia. Also assess the sexual maturity of adolescents. Look for abdominal tenderness, guarding, and masses. In most cases of CD and UC, abdominal tenderness is minimal, but a tender right lower quadrant mass resulting from inflamed, thickened bowel may be found in CD. Severe abdominal tenderness with distention and guarding is an ominous sign indicating toxic megacolon or bowel perforation. The presence of oral ulcers or perianal skin tags, abscesses, or fistulas are typical of CD. Do not forget to look for the extraintestinal manifestations listed in Table 61-5.

What Studies Should I Order for Suspected Inflammatory Bowel Disease?

Start with a complete blood count (CBC), erythrocyte sedimentation rate (ESR), and C-reactive protein. Serum albumin and liver function tests should also be determined. Low serum albumin indicates chronic GI loss of protein and poor nutritional status. Elevation of liver enzymes may suggest accompanying sclerosing cholangitis or autoimmune hepatitis. Patients who appear acutely ill should have serum electrolytes, blood urea nitrogen (BUN), and creatinine measured. Patients with diarrhea should have stool sent for culture and Clostridium difficile toxin assay. Always test stool for blood.