AANP Family Nurse Practitioner (FNP) Certification ExamDiagnosisMedium
A 24-year-old female presents with recurrent episodes of abdominal pain, bloating, and alternating constipation and diarrhea for the past 8 months. The pain is often relieved by defecation. She denies weight loss, fever, or blood in her stool. Her physical exam is unremarkable, and recent stool studies, CBC, and thyroid panel are all normal. What is the most likely diagnosis?
- ALactose Intolerance
- BCeliac Disease
- CIrritable Bowel Syndrome (IBS)
- DInflammatory Bowel Disease (IBD)
Show answer & explanationAnswer & explanation
Correct answer: C. Irritable Bowel Syndrome (IBS)
The patient's chronic history of abdominal pain related to defecation, bloating, and altered bowel habits (alternating constipation and diarrhea), in the absence of 'red flag' symptoms (weight loss, fever, blood in stool) and with normal lab findings, is classic for Irritable Bowel Syndrome (IBS).
Why the other options are wrong
- A. Lactose intolerance primarily causes bloating, gas, and diarrhea after consuming dairy, but not typically chronic alternating constipation and diarrhea, or pain relieved by defecation as the primary complaint.
- B. Celiac disease would cause malabsorption symptoms, weight loss, and often specific antibody markers, which are not described.
- D. IBD (Crohn's or ulcerative colitis) would typically present with inflammatory markers, weight loss, and often bloody stools, none of which are present here.
Irritable Bowel Syndrome (IBS)
A common functional gastrointestinal disorder characterized by chronic abdominal pain and altered bowel habits (constipation, diarrhea, or both) without any identifiable organic cause.
- Diagnosis is based on symptom criteria (Rome IV), absence of 'red flag' symptoms, and normal routine labs.
- Pain is typically related to defecation.
- No inflammation, structural damage, or specific biomarkers.
Memory trick: IBS: Irritable Bowel Syndrome is a 'Stress'ful, 'Symptoms-only' diagnosis.