A woman aged 19 years has a three-year history of recurrent chronic abdominal pain and diarrhea. Esophagogastroduodenoscopy (EGD), colonoscopy, complement fixation, celiac, sonogram, gynecologic workup and routine labs have all been negative.

A lactose-free diet resulted in slight improvement. She was treated empirically after a positive stool culture for a parasite that may or may not cause symptoms, which seemed to help for a while. What steps should be taken next? — Tina Clark, CRNP, Owings Mills, Md.

First, assess whether her symptoms fit the Rome III criteria for functional GI disorders, specifically irritable bowel syndrome (IBS) (available at www.romecriteria.org/assets/pdf/19_RomeIII_apA_885-898.pdf, accessed September 15, 2011). Does she have symptom-free days? Are there any abnormalities on physical exam (e.g., weight loss)? Are there any red flags in her history (e.g., nighttime symptoms)?

Second, find out what type of celiac testing she had (blood test or biopsy) and the exact results. Does she have a family history of celiac disease? Did she try a strict gluten-free diet as a trial?

Third, determine exactly what labs she had done. What stool studies were done? What was the parasite that she tested positive for? Did she have stool tests for possible osmotic diarrhea? Did she have multiple biopsies from her EGD and colonoscopy?

Finally, find out whether she had a breath test for small-bowel bacterial overgrowth, which can be associated with irritable bowel syndrome. It would be helpful to know if she had a small-bowel series or capsule endoscopy as well. — Sharon Dudley-Brown, PhD, FNP-BC, co-director, gastroenterology & hepatology, nurse practitioner fellowship program, Johns Hopkins University Schools of Medicine & Nursing, Baltimore (156-5)