A 36-year-old man comes to the office due to frequent "loose stools" for the past 10 months. The patient describes stools that are large in volume, liquid to semisolid, occurring up to 3-4 times a day, and often foul-smelling. He also reports excessive flatulence and occasional nausea and abdominal cramping. The patient says he may have lost some weight because his clothes are much looser than before. He has no prior medical problems and takes no medications. Family history is notable for hypertension and coronary artery disease in his father. The patient immigrated to the United States from Italy with his family when he was 2 years old and has not traveled out of the country since then. He does not use tobacco or illicit drugs and drinks alcohol occasionally. The patient works in a family-owned restaurant and has had no sick contacts. He consumes a balanced diet and notes no specific association of diarrhea to food. The patient has been in a monogamous relationship with his wife for the past 10 years. Temperature is 36.6 C (97.9 F), blood pressure is 130/86 mm Hg, and pulse is 72/min. Weight is 63.5 kg (140 lb). The sclerae are anicteric, and mucous membranes are moist without any lesions. Cardiopulmonary examination is unremarkable. The abdomen is soft, nondistended, and nontender, with no organomegaly. Bowel sounds are increased. Rectal examination shows no masses or tenderness and an empty rectal vault. Stool occult blood testing is negative. Samples for blood count, erythrocyte sedimentation rate, TSH, and serum electrolytes are obtained.
Which of the following additional interventions is most appropriate in management of this patient's diarrhea?

Question

A 36-year-old man comes to the office due to frequent "loose stools" for the past 10 months.  The patient describes stools that are large in volume, liquid to semisolid, occurring up to 3-4 times a day, and often foul-smelling.  He also reports excessive flatulence and occasional nausea and abdominal cramping.  The patient says he may have lost some weight because his clothes are much looser than before.  He has no prior medical problems and takes no medications.  Family history is notable for hypertension and coronary artery disease in his father.  The patient immigrated to the United States from Italy with his family when he was 2 years old and has not traveled out of the country since then.  He does not use tobacco or illicit drugs and drinks alcohol occasionally.  The patient works in a family-owned restaurant and has had no sick contacts.  He consumes a balanced diet and notes no specific association of diarrhea to food.  The patient has been in a monogamous relationship with his wife for the past 10 years.  Temperature is 36.6 C (97.9 F), blood pressure is 130/86 mm Hg, and pulse is 72/min.  Weight is 63.5 kg (140 lb).  The sclerae are anicteric, and mucous membranes are moist without any lesions.  Cardiopulmonary examination is unremarkable.  The abdomen is soft, nondistended, and nontender, with no organomegaly.  Bowel sounds are increased.  Rectal examination shows no masses or tenderness and an empty rectal vault.  Stool occult blood testing is negative.  Samples for blood count, erythrocyte sedimentation rate, TSH, and serum electrolytes are obtained. 
Which of the following additional interventions is most appropriate in management of this patient's diarrhea?

Quizplus · Accepted Answer

Explanation: The patient is suffering from chronic diarrhea, which is defined as the production of loose stools with or without increased frequency for >4 weeks. In high-income countries, some of the most common causes include irritable bowel syndrome, inflammatory bowel disease, chronic infection, and malabsorption syndromes such as celiac disease and lactose intolerance. With the appropriate evaluation, the specific cause can be found in approximately 90% of patients. The first step in the evaluation and management of chronic diarrhea is taking a comprehensive history, including a clear description of stool characteristics, duration and timing of symptoms, travel history, weight loss, systemic symptoms (eg, fever, arthralgias), and medication history. This typically will provide specific clues to the diagnosis and help direct further investigations. In addition to routine laboratory tests, stool analysis can yield important information about the etiology of the diarrhea. Evaluation should also include microscopic stool examination for leukocytes and parasites, occult blood, pH, staining for fat, and electrolyte analysis for calculating the osmotic gap. (Choice A) Although an empiric trial of a lactose-free diet may be considered in appropriate patients, this patient lacks common symptoms of lactose intolerance such as a correlation between the diarrhea and consumption of lactose-containing foods. In addition, weight loss is not usually associated with lactose intolerance. (Choice B) Many causes of chronic diarrhea ultimately require biopsy confirmation; however, it should not be performed until after stool analysis as some causes do not require invasive tests. (Choice C) Radiographic imaging, including CT scan of the abdomen, is not indicated in the initial evaluation of chronic diarrhea as it is unlikely to provide useful diagnostic information. (Choice D) Unless a comprehensive evaluation has proven inconclusive or a patient has severe symptoms, the use of symptomatic therapy (eg, loperamide) to control chronic diarrhea without a specific diagnosis is not recommended. Educational objective: The evaluation and management of chronic diarrhea involves a comprehensive history (eg, clear description of stool characteristics, duration and timing of symptoms), basic serum analysis, and, importantly, stool analysis. References: American Gastroenterological Association medical position statement: guidelines for the evaluation and management of chronic diarrhea. (http://www.ncbi.nlm.nih.gov/pubmed/10348831) Evaluation of chronic diarrhea. (http://www.ncbi.nlm.nih.gov/pubmed/22085666)

A 36-Year-Old Man Comes to the Office Due to Frequent