How Should a Patient With Chronic Abdominal Pain Be Evaluated?

Answer in brief: Chronic abdominal pain is evaluated most efficiently by first identifying alarm features and a symptom pattern that points toward structural, inflammatory, pancreaticobiliary, vascular, gynecologic, metabolic or abdominal-wall disease. When these are absent and appropriate targeted testing is negative, a positive diagnosis of a disorder of gut-brain interaction is preferable to endless exclusionary testing.[1]

The first decision is structural risk versus a likely disorder of gut-brain interaction

History should define location, timing, relation to meals and defecation, nocturnal symptoms, weight loss, vomiting, bleeding, fever, bowel-pattern change, prior surgery and medication exposures. Examination should look for focal peritonism, masses, hernia, abdominal-wall pain, neuropathic patterns and extraintestinal clues.

Alarm features change the pathway

GI bleeding or iron-deficiency anemia.
Progressive unintentional weight loss.
Persistent vomiting or obstructive symptoms.
Nocturnal symptoms that are new or progressive.
Fever, inflammatory markers or objective malnutrition.
New symptoms at an older age or strong cancer family history.
Abnormal examination or significant laboratory abnormalities.

Target testing to the phenotype

Right-upper-quadrant or biliary-type pain calls for hepatobiliary evaluation; epigastric pain with weight loss or vomiting may need upper endoscopy and/or imaging; postprandial pain with vascular risk raises mesenteric ischemia; chronic pancreatitis requires attention to alcohol, smoking, recurrent pancreatitis, calcification and exocrine dysfunction. Lower abdominal pain with bowel-pattern change may fit IBS after appropriate screening, but inflammatory disease, celiac disease, microscopic colitis and colorectal disease should be considered when features point that way.

Remember abdominal wall pain

Carnett testing is simple and underused. Pain that remains the same or worsens when the abdominal wall is tensed suggests a somatic abdominal-wall source rather than a visceral one. Focal trigger points, prior surgery and nerve-entrapment syndromes can explain long histories of “unexplained GI pain.”

When the evaluation is negative, make a positive diagnosis

AGA advice for chronic GI pain in disorders of gut-brain interaction emphasizes a biopsychosocial formulation, a durable clinician-patient relationship and avoidance of opioids.[1] The diagnosis should not be presented as “nothing is wrong.” Visceral hypersensitivity, altered central pain processing, motility changes and behavioral amplification are real mechanisms that can be treated.

Management principles after organic disease is reasonably excluded

Explain the working diagnosis and expected course.
Treat the dominant bowel disorder, reflux, dyspepsia or constipation where present.
Use diet selectively rather than imposing broad restrictions.
Consider gut-brain behavioral therapy and central neuromodulators for persistent pain.
Avoid chronic opioids because they can worsen GI function and pain over time.
Create a follow-up plan with explicit triggers for reevaluation.

Common mistake

The costly error is repeating CT scans, endoscopies and laboratory panels each time symptoms recur without a new clinical signal. Reassessment is appropriate when the phenotype changes; otherwise, repeated exclusionary testing can reinforce illness behavior and expose patients to risk without improving outcomes.[1]

Questions trainees should be able to answer

What are the highest-value alarm features in chronic abdominal pain?
How is Carnett testing used?
Why is a positive diagnosis of a disorder of gut-brain interaction better than “diagnosis by exhaustion”?

Frequently asked questions

Does normal imaging rule out important disease? No. Endoscopic, mucosal, motility and functional disorders may have normal CT imaging.

Should chronic abdominal pain be treated with opioids? Generally no. Chronic opioids can worsen constipation, motility and centrally mediated pain and are discouraged in disorders of gut-brain interaction.[1]

When should testing be repeated? When new alarm features, objective abnormalities or a meaningful change in symptom pattern develops.

Free further reading from Dr. Thomson

GI Practice Review — free book library
First Principles of Gastroenterology and Hepatology — free book library

References

1. Keefer L, Ko CW, Ford AC. AGA Clinical Practice Update on Management of Chronic Gastrointestinal Pain in Disorders of Gut-Brain Interaction: Expert Review. Clin Gastroenterol Hepatol. 2021;19:2481-2488.e1. doi:10.1016/j.cgh.2021.07.006.

2. Thomson ABR. Practice Review in Gastroenterology. CAPstone Academic Publishers; 2014.

3. Thomson ABR. First Principles of Gastroenterology and Hepatology in Adults and Children. 7th ed. CAPstone Academic Publishers; 2013.

Educational use only. This article is intended for clinicians and trainees and does not replace patient-specific medical judgment or local guidance.