What is the appropriate workup and treatment for a 16-year-old female presenting with stomach upset to a pediatrician?

Workup for 16-Year-Old Female with Stomach Upset

Initial Clinical Assessment

Begin with a focused history targeting alarm features that mandate immediate investigation: weight loss, recurrent vomiting, gastrointestinal bleeding, anemia, dysphagia, jaundice, palpable mass, bilious vomiting, fever, or nocturnal symptoms that wake the patient from sleep 1. The absence of these features allows for a symptom-based diagnosis without extensive testing 1.

Key Historical Elements to Elicit

• Pain characteristics: Location (periumbilical vs. localized), timing relative to meals, relationship to defecation, and whether pain is relieved by bowel movements 1
• Bowel pattern changes: Frequency, consistency (loose vs. hard), urgency, sensation of incomplete evacuation, and presence of mucus 1
• Associated symptoms: Bloating, distension, nausea, early satiety, postprandial fullness 1, 2
• Dietary triggers: Lactose-containing products, high FODMAP foods (wheat, dairy, onions, certain fruits), caffeine, alcohol 1, 2
• Psychological factors: Recent stressors, anxiety, depression, sleep disturbance, history of abuse, school attendance patterns 1
• Menstrual history: Relationship of symptoms to menstrual cycle, dysmenorrhea, sexual activity 3
• Medication use: NSAIDs, antibiotics, or other medications that could cause gastrointestinal symptoms 1

Physical Examination Focus

• General appearance: Observe how the patient presents herself—does she appear comfortable or in distress? 3
• Abdominal examination: Tenderness location and severity, rebound, guarding, masses, organomegaly, bowel sounds 1, 3
• Extraintestinal manifestations: Signs of weight loss, pallor suggesting anemia, jaundice 1

Laboratory and Diagnostic Testing

For a 16-year-old without alarm features and with symptoms consistent with functional gastrointestinal disorder, limited investigation is appropriate 1.

Initial Laboratory Panel

• Complete blood count: To exclude anemia 1
• Celiac serology (tissue transglutaminase IgA with total IgA): Recommended in all patients with suspected IBS-type symptoms 1, 4
• Inflammatory markers (ESR or CRP): If inflammatory bowel disease is a consideration 1
• Thyroid function tests: To exclude hyperthyroidism as a cause of diarrhea-predominant symptoms 1
• Stool studies: Only if diarrhea is prominent—consider fecal calprotectin, ova and parasites, Giardia antigen 1
• Urinalysis: To exclude urinary tract pathology 1, 3

When to Perform Endoscopy

Endoscopy is NOT indicated in a 16-year-old with typical functional symptoms and no alarm features 1. The age threshold for endoscopy based on gastric cancer risk is 45-50 years in Western populations 1. However, consider upper endoscopy if:

• Symptoms are refractory to initial treatment after 4-6 weeks 4
• Dysphagia is present 1
• There is concern for eosinophilic esophagitis based on food allergies or dysphagia 5
• Persistent vomiting raises concern for anatomical abnormalities 1, 6

Advanced Imaging

Avoid routine imaging in uncomplicated cases 1. Reserve CT abdomen/pelvis for:

• Refractory symptoms after 4-6 weeks of appropriate treatment 4
• Development of new alarm features 4
• Concern for surgical pathology (appendicitis, ovarian pathology) 7, 3

Upper GI series is NOT useful for diagnosing functional disorders as it is too brief to capture pathologic reflux and has high false-positive rates 1.

Diagnostic Approach Based on Symptom Pattern

If Symptoms Suggest IBS (Abdominal Pain + Altered Bowel Habits)

Make a positive diagnosis using Rome IV criteria rather than diagnosis of exclusion 1, 4:

• At least 12 weeks (not necessarily consecutive) in the last 12 months of abdominal pain with two of three features: relieved by defecation, associated with change in stool frequency, or associated with change in stool consistency 1
• Supportive features include female sex, age <45 years, symptom duration >2 years, and frequent healthcare visits for non-GI complaints 1

If Symptoms Suggest GERD (Heartburn, Regurgitation)

In adolescents with typical reflux symptoms, a clinical diagnosis is reliable without testing 1. Consider:

• Trial of proton pump inhibitor (omeprazole 20 mg once daily before meals for 4-8 weeks) 8
• If symptoms persist despite PPI therapy or dysphagia is present, proceed to endoscopy to evaluate for eosinophilic esophagitis or erosive esophagitis 1, 5

If Episodic Vomiting is Prominent

Consider cyclic vomiting syndrome if there is a pattern of stereotypical episodes 1:

• Obtain detailed cannabis use history—distinguish between recreational use and heavy daily use (>4 times weekly for >1 year) that would suggest cannabinoid hyperemesis syndrome 1
• Basic metabolic panel, glucose, lipase, and liver function tests during or immediately after an episode 1
• Brain imaging only if localizing neurologic symptoms are present 1

Initial Management Strategy

First-Line Interventions (Implement Immediately)

Dietary modifications should be patient-centered and initiated before pharmacotherapy 1, 2:

• Eliminate common triggers: Temporarily remove lactose-containing products, alcohol, caffeine, and high-osmolar supplements 2
• Eating pattern: Frequent small meals of easily digestible foods (bananas, rice, applesauce, toast) 2
• Soluble fiber: Start ispaghula 3-4 g/day, gradually increase to avoid bloating; avoid insoluble fiber like wheat bran 1, 2

Lifestyle counseling 1:

• Regular physical activity improves GI symptoms 4
• Adequate sleep hygiene 1
• Mindful eating practices 1

Pharmacological Management

For abdominal pain with meal-related exacerbation 4, 2:

• Antispasmodics (hyoscine butylbromide or dicyclomine) as first-line for cramping pain 2
• Loperamide 4 mg initially, then 2 mg after each unformed stool if diarrhea is prominent 2

For persistent symptoms after 2-4 weeks of conservative management 1, 2:

• Low-dose tricyclic antidepressant: Amitriptyline 10 mg at bedtime, titrate slowly to 30-50 mg for pain relief 1, 2
• This dose treats GI pain but is insufficient for mood disorders; if moderate-to-severe anxiety or depression is present, use therapeutic-dose SSRI instead 1, 9

Second-Line Dietary Intervention

Low FODMAP diet should be supervised by a trained dietitian 1, 2:

• Consider only after first-line measures fail 2
• Contraindications: Eating pathology, severe mental illness, or nutritional deficiency 1
• Efficacy is 70-86% in controlled trials 9
• If moderate-to-severe anxiety or depression coexists, consider Mediterranean diet instead 1

Psychological Assessment and Management

Screen systematically for psychiatric comorbidity using validated tools (Patient Health Questionnaire-9 for depression, GAD-7 for anxiety) 9:

• Up to one-third of IBS patients have mental health comorbidity requiring integrated treatment 1, 9
• Depression, anxiety, and somatization are common but do not reliably distinguish IBS from organic disease 1

Indications for Psychological Referral

Refer to gastropsychologist or mental health specialist if 1:

• Moderate-to-severe depression or anxiety symptoms 1
• Suicidal ideation or hopelessness 1
• Low social support system 1
• Impaired quality of life or avoidance behavior 1
• History of abuse 1
• Motivational deficiencies affecting self-management 1

Brain-gut behavioral therapies (cognitive behavioral therapy, gut-directed hypnotherapy, mindfulness-based stress reduction) should be initiated alongside pharmacotherapy for patients with mood disorders 1, 2, 9.

Critical Pitfalls to Avoid

• Do not perform exhaustive testing in young patients without alarm features—this delays diagnosis, increases costs, and reinforces illness behavior 1, 9
• Avoid opioid analgesics for chronic abdominal pain due to addiction risk and worsening of GI motility 4, 2
• Do not use low-dose TCAs to treat comorbid mood disorders—doses of 10-30 mg are insufficient for anxiety/depression 1, 9
• Do not implement low FODMAP diet without dietitian supervision, especially in patients with eating pathology or severe mental illness 1, 9
• Do not repeat endoscopy or imaging without new alarm features or significant change in clinical presentation 1

Follow-Up and Monitoring

Schedule frequent initial visits 9:

• Follow up at 2-4 weeks initially to assess response to interventions 9
• Reassess both GI and psychological symptoms at each visit 9
• Provide reassurance of benign prognosis and ongoing involvement in care 1, 9

Indications for Gastroenterology Referral

Refer to gastroenterology if 1, 4:

• Symptoms remain severe or refractory after 4-6 weeks of appropriate treatment 4
• Diagnosis is uncertain despite initial workup 1
• New alarm features develop 4
• Patient requires specialized dietary counseling or advanced therapies 1