What is the appropriate evaluation and management of rectal bleeding in a 14-year-old patient?

Evaluation and Management of Rectal Bleeding in a 14-Year-Old

In a 14-year-old with rectal bleeding, perform colonoscopy rather than sigmoidoscopy alone, as 22% of polyps and significant pathology would be missed with limited examination, and inflammatory bowel disease is the most common serious diagnosis in this age group. 1

Initial Assessment

History and Physical Examination

• Assess for systemic symptoms including fever, abdominal pain, diarrhea, weight loss, or failure to thrive, as these indicate serious underlying pathology requiring urgent gastroenterology referral 2
• Evaluate bleeding characteristics: bright red blood suggests anorectal source or hemorrhoids, while darker blood mixed with stool indicates more proximal pathology 3
• Perform digital rectal examination to assess for masses, fissures, or stool consistency 2
• Always consider child abuse when bleeding presents with other concerning features 2

Laboratory Evaluation

• Obtain complete blood count (hemoglobin, hematocrit, platelet count) to assess bleeding severity 4, 2
• Check basic metabolic panel if dehydration or significant bleeding is present 2
• Consider coagulation studies (PT/INR, aPTT) if there is personal or family history of easy bruising or excessive bleeding 2

Risk Stratification

While the Oakland score was developed for adults and has not been validated in pediatric populations, approximately 15% of acute presentations with bright red rectal bleeding in children involve hypovolemic shock, requiring aggressive fluid resuscitation 2. Immediate stabilization takes priority over diagnostic workup in unstable patients.

Diagnostic Approach

Endoscopic Evaluation

Colonoscopy is the investigation of choice for prolonged or recurrent rectal bleeding in adolescents 1. The rationale is compelling:

• Inflammatory bowel disease and polyps are the most prevalent diagnoses in pediatric patients with rectal bleeding 1
• In 22% of cases, polyps would be missed if only sigmoidoscopy were performed 1
• Colonoscopy provides both diagnostic and therapeutic capabilities with a safe profile 1

Upper Endoscopy Consideration

If the patient presents with accompanying complaints such as abdominal pain or diarrhea, perform ileocolonoscopy combined with esophagogastroduodenoscopy, as this combines high diagnostic yield with a safe procedure 1. Remember that 10-15% of patients with severe hematochezia have an upper GI bleeding source 2.

Age-Specific Differential Diagnoses

Most Common Causes in Adolescents

• Inflammatory bowel disease (particularly Crohn's disease) - most common serious diagnosis in patients under 50 years 5, 1
• Polyps 1
• Hemorrhoids and anal fissures 3
• Food protein-induced enterocolitis syndrome (FPIES) - though more common in younger children 2

Rare but Important

• Colorectal cancer is extremely rare in patients younger than 50 years 5
• Angiodysplasia 5

Critical Pitfalls to Avoid

• Never assume hemorrhoids without proper evaluation, as symptoms attributed to hemorrhoids frequently represent other pathology 2
• Do not rely on sigmoidoscopy alone, as this misses more than one-fifth of polyps 2
• Do not attribute positive fecal occult blood tests to hemorrhoids without complete colonic evaluation 6
• A normal digital rectal examination does not exclude significant pathology - abnormal findings were present in 52% of patients with normal rectal exams in one study 7

Timing of Endoscopy

For stable patients with rectal bleeding, outpatient colonoscopy is appropriate 4. However, given that inflammatory bowel disease is the leading serious diagnosis in this age group and can progress rapidly, expedited evaluation within 2 weeks is reasonable for persistent or recurrent bleeding 4, 1.