What is the initial approach for a patient presenting with enterocolitis, including history and physical (H&P) examination?

History and Physical Examination for Enterocolitis

Initial Clinical Assessment

Begin with a focused history targeting symptom onset, character, and severity, followed by systematic physical examination to identify signs of bowel ischemia, perforation, or systemic toxicity. 1

Critical History Components

Symptom Characterization:

• Diarrhea pattern: frequency, consistency, presence of blood or mucus, and timing of onset 1, 2
• Abdominal pain: location, severity, character, and progression 1, 3
• Vomiting: timing (particularly if repetitive or projectile), relationship to food intake 1, 4
• Constitutional symptoms: fever, weight loss, fatigue 1
• Nocturnal symptoms: diarrhea or urgency at night suggests organic disease 2
• Rectal symptoms: urgency, tenesmus, incontinence, rectal bleeding 1, 2

Temporal Pattern:

• Duration of symptoms: hours to days helps differentiate acute infectious from chronic inflammatory causes 1, 3
• Previous episodes: 30-40% of patients with certain forms report prior similar episodes 1
• Symptom progression: rapid deterioration suggests ischemia or perforation 1

Essential Risk Factor Assessment

Infectious and Environmental Exposures:

• Recent travel history: destinations and timing relative to symptom onset 2, 3
• Infectious contacts: exposure to individuals with enteric infections 2
• Sexual practices: relevant for certain infectious differential diagnoses 1, 2, 3
• Antibiotic use: recent or current antibiotics increase risk of C. difficile 1, 2

Medical and Medication History:

• Immunosuppression status: chemotherapy, immune checkpoint inhibitors, chronic immunosuppressive therapy 1, 5
• NSAID use: can exacerbate inflammatory bowel disease 2
• Previous bowel surgery or inflammatory bowel disease: increases risk of recurrence 1, 2
• Family history: inflammatory bowel disease or colorectal cancer in first-degree relatives 1, 2

Age-Specific Considerations:

• Neonates/infants: prematurity, low birth weight, feeding history (formula vs. breast milk) for necrotizing enterocolitis 5, 6
• Adults: smoking status (protective in ulcerative colitis, risk factor if former smoker) 2

Physical Examination

Vital Signs and General Assessment

Systematic vital sign evaluation is mandatory:

• Pulse and blood pressure: tachycardia and hypotension suggest hypovolemia or sepsis 1
• Temperature: fever indicates infection or severe inflammation 1
• Weight: document for comparison and assess for acute loss 1
• Respiratory rate: tachypnea may indicate metabolic acidosis or sepsis 1

Abdominal Examination

Sequential examination to detect peritonitis, obstruction, or ischemia:

• Inspection: distension (classic finding in many forms), asymmetric distension, visible peristalsis 1
• Auscultation: diminished or absent bowel sounds suggest ileus or peritonitis; high-pitched sounds suggest obstruction 1
• Palpation: tenderness location and severity, guarding, rigidity, rebound tenderness 1
• Percussion: tympany suggests gaseous distension; shifting dullness suggests ascites 1

Critical finding: Absence of peritonitis does NOT exclude bowel ischemia—this is a common pitfall that can delay diagnosis 1

Rectal Examination

Digital rectal examination provides essential diagnostic information:

• Stool characteristics: presence of blood, mucus, or melena 1, 3
• Rectal vault: often empty in obstructive processes like sigmoid volvulus 1
• Perianal inspection: fissures, fistulas, or skin tags suggest inflammatory bowel disease 1

Initial Laboratory Evaluation

Obtain comprehensive laboratory panel immediately:

• Complete blood count: leukocytosis (infection), thrombocytosis (chronic inflammation), anemia (chronic disease or bleeding) 1
• Inflammatory markers: C-reactive protein and ESR (CRP >10 mg/L predicts severe disease) 1
• Electrolytes and renal function: assess dehydration and metabolic derangements 1
• Liver function tests: evaluate for hepatobiliary involvement 1
• Blood gas and lactate: elevated lactate suggests bowel ischemia or sepsis 1
• Albumin: hypoalbuminemia indicates severe or chronic inflammation 1

Stool studies are essential:

• Bacterial culture: Salmonella, Shigella, Campylobacter, E. coli O157:H7 3
• C. difficile toxin: test with every flare or in antibiotic-exposed patients 1, 2
• Ova and parasites: based on travel history and risk factors 5, 3
• Fecal calprotectin: elevated in intestinal inflammation, useful for monitoring 1, 2

Common Pitfalls to Avoid

Diagnostic errors that worsen outcomes:

• Delaying evaluation in elderly or institutionalized patients: these populations often have atypical presentations with minimal peritoneal signs despite advanced disease 1
• Assuming normal physical examination excludes serious pathology: abdominal distension may mask peritonitis, and bowel ischemia can exist without peritoneal signs 1
• Missing infectious triggers during disease flares: always test for C. difficile and consider CMV in immunosuppressed patients 1, 2
• Overlooking medication-induced causes: immune checkpoint inhibitors can cause enterocolitis weeks to months after initiation 1
• Failing to recognize hypovolemic shock in food protein-induced enterocolitis syndrome: 15-20% of severe cases progress to shock requiring aggressive fluid resuscitation 1, 4