I have had persistent abdominal pain for a week; what evaluation and management is recommended?

Evaluation and Management of Persistent Abdominal Pain for One Week

For stomach pain persisting one week, you should undergo a focused evaluation to exclude alarm features requiring urgent intervention, followed by targeted testing based on pain location and associated symptoms, with most cases ultimately representing functional disorders that respond to neuromodulators rather than repeated imaging. 1, 2

Initial Assessment: Identify Alarm Features

Your first priority is determining whether alarm features are present that mandate urgent evaluation 1:

• Weight loss - suggests malignancy or inflammatory bowel disease 1
• Rectal bleeding or blood in stool - requires colonoscopy to exclude colorectal cancer 3, 1
• Iron deficiency anemia - indicates chronic blood loss 3, 1
• Nocturnal symptoms that wake you from sleep - suggests organic disease 1
• Change in stool caliber - raises concern for obstructive lesion 3
• Right lower quadrant pain - requires urgent evaluation to exclude appendicitis, inflammatory bowel disease, or cecal pathology 1

If any alarm features are present, proceed immediately to imaging (CT abdomen/pelvis with oral and IV contrast) and/or colonoscopy rather than empiric treatment. 3, 1

Focused History: Pain Characteristics

Document specific pain features that narrow the differential 2, 4:

• Relationship to meals: Pain immediately after eating suggests gastric ulcer; pain 2-3 hours after eating or at night suggests duodenal ulcer; pain improved by eating suggests ulcer disease 4
• Relationship to defecation: Pain relieved by bowel movements strongly suggests irritable bowel syndrome 3, 1
• Pain radiation to back: Suggests chronic pancreatitis or posterior duodenal ulcer 4
• Associated with change in stool frequency or consistency: Supports IBS diagnosis 3, 1
• Epigastric burning/heartburn: Suggests GERD or functional dyspepsia 4

Basic Laboratory Testing

Obtain the following labs to exclude organic disease 2:

• Complete blood count - detects anemia or elevated white blood cell count 2
• C-reactive protein - if >140 mg/L with fever, consider infectious/inflammatory process 3
• Liver function tests - screens for hepatobiliary disease 2
• Thyroid-stimulating hormone - hypothyroidism causes constipation-predominant symptoms 1
• Celiac serology (tissue transglutaminase IgA) - if diarrhea-predominant symptoms 1

Imaging and Endoscopy: When to Pursue

Avoid reflexive imaging in the absence of alarm features, as most chronic abdominal pain represents functional disorders. 2, 5 However, specific scenarios warrant investigation:

• Upper endoscopy: Indicated for persistent epigastric pain, dysphagia, or suspected peptic ulcer disease 3
• Colonoscopy: Required for alarm features (bleeding, anemia, weight loss) or age-appropriate screening 3, 1
• CT abdomen/pelvis: Consider if pain is severe, localized, or associated with fever/elevated inflammatory markers 3, 2
• Sigmoidoscopy with biopsies: For diarrhea-predominant symptoms to detect microscopic colitis 1

Critical pitfall: Once functional diagnosis is established, avoid repeated costly investigations, as this reinforces illness behavior and delays appropriate treatment 2, 5

Functional Disorders: Most Likely Diagnosis

If alarm features are absent and basic testing is unremarkable, you likely have a disorder of gut-brain interaction 3, 5:

Irritable Bowel Syndrome - requires recurrent abdominal pain at least 1 day per week for 3 months, associated with two or more of: pain related to defecation, change in stool frequency, or change in stool form 3, 1

Functional Dyspepsia - epigastric pain or burning not necessarily related to meals, may occur during fasting 4

Centrally Mediated Abdominal Pain Syndrome - chronic abdominal pain without clear relationship to bowel function, often involving central sensitization 3, 2

Treatment: Pharmacologic Approach

For functional abdominal pain, tricyclic antidepressants are first-line therapy, starting at low doses (10-25 mg nortriptyline or amitriptyline at bedtime) and titrating slowly. 3, 2 These work as gut-brain neuromodulators, not antidepressants, by modulating visceral pain perception 3.

Additional pharmacologic options based on predominant symptoms:

• Constipation-predominant: Linaclotide (most effective, high-quality evidence for FDA responder definition) 3, dietary fiber 25 g/day 1, or plecanatide 3
• Diarrhea-predominant: Loperamide for symptom control 3
• Meal-related pain: Antispasmodics (dicyclomine, hyoscyamine) 2
• If tricyclics not tolerated: SSRIs as second-line, or SNRIs for severe symptoms 2

Absolute contraindication: Never use opioids for chronic functional abdominal pain, as they worsen gastric emptying, cause narcotic bowel syndrome, and create addiction risk. 3, 2

Non-Pharmacologic Therapies

Consider these approaches early, particularly if pain persists beyond 12 months 3, 2:

• Cognitive behavioral therapy - addresses psychological perpetuation of pain 3, 6
• Gut-directed hypnotherapy - effective for visceral hypersensitivity 2
• Dietary modifications: Identify food intolerances, ensure adequate time for defecation, appropriate exercise 1

Setting Expectations

Explain that pain perception is real but multifactorial, involving both peripheral gut factors and central nervous system processing. 3, 2 This framing prevents patients from feeling dismissed while establishing realistic treatment goals focused on pain management rather than complete elimination 3.

Monitor for hypervigilance to pain and avoid reinforcing illness behavior through excessive testing once functional diagnosis is established 2, 5.