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. The patient comes for a follow-up visit 2 weeks later. He continues to have large-volume, foul-smelling stools but has had no new symptoms. The patient recollects that his weight was about 75 kg (165 lb) prior to the onset of symptoms, and he has lost more than 5 kg (11 lb). Physical examination findings are unchanged. Laboratory testing performed during the previous visit is notable for the following: Stool studies revealed a high osmotic gap. Further laboratory studies are ordered. Gastrointestinal endoscopy with biopsy is most likely to reveal which of the following?

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. The patient comes for a follow-up visit 2 weeks later.  He continues to have large-volume, foul-smelling stools but has had no new symptoms.  The patient recollects that his weight was about 75 kg (165 lb) prior to the onset of symptoms, and he has lost more than 5 kg (11 lb).  Physical examination findings are unchanged.  Laboratory testing performed during the previous visit is notable for the following:  Stool studies revealed a high osmotic gap.  Further laboratory studies are ordered.  Gastrointestinal endoscopy with biopsy is most likely to reveal which of the following?

Quizplus · Accepted Answer

Explanation: 11ec2b69_bf21_3e11_8f63_9d029ccffff7_MD0005_00 Chronic malabsorption is characterized by greasy, large-volume diarrhea and weight loss. Celiac disease ([CD] gluten-sensitive enteropathy) results in chronic malabsorption with large-volume, foul-smelling stools; excessive flatulence; weight loss; and microcytic anemia. In many patients, the only presenting feature is iron deficiency anemia. Other common malabsorption syndromes include lactose intolerance, chronic pancreatitis, and bacterial overgrowth of the small intestine. This patient most likely has CD, which results in osmotic diarrhea (elevated osmotic gap) and most commonly occurs in patients age 10-40. Unlike in lactose intolerance and chronic pancreatitis, patients may not associate the diarrhea with meals or specific foods. In addition, patients with chronic pancreatitis frequently report significant abdominal pain. Although anemia is also seen in small intestinal bacterial overgrowth, the anemia is more frequently macrocytic due to vitamin B₁₂ deficiency (Choice B). elevated osmotic gap ₁₂ Diagnostic evaluation of CD depends on the patient's pretest probability of having the disease; however, for most patients with reasonable clinical suspicion for disease, workup involves both serologic studies (eg, immunoglobulin A anti-tissue transglutaminase) and small bowel biopsy. Biopsies are usually taken from the distal duodenum during upper endoscopy. Common histologic findings include villous atrophy, loss of the normal villus architecture, intraepithelial lymphocytic infiltrates, and crypt hyperplasia. (Choice A) Collagenous colitis is characterized by chronic, watery diarrhea and is commonly associated with fecal urgency and nocturnal diarrhea, which this patient lacks. In addition, the diarrhea is secretory (decreased osmotic gap). Biopsy demonstrates a thick subepithelial collagen band. (Choice C) Irritable bowel syndrome typically presents with chronic abdominal pain and altered bowel habits. Weight loss is rare and should prompt evaluation for other causes of gastrointestinal symptoms. Giardiasis may cause a similar presentation to that seen with this patient, but endoscopy would typically reveal trophozoites, sometimes with nonspecific changes (eg, villous flattening). (Choice D) Inflammatory bowel disease such as Crohn disease presents with abdominal pain and bloody diarrhea (may not be grossly bloody). In addition, inflammatory markers such as the erythrocyte sedimentation rate are commonly elevated. Educational objective: Celiac disease (gluten-sensitive enteropathy) is characterized by large-volume, foul-smelling stools; excessive flatulence; weight loss; and microcytic anemia. Evaluation involves both serologic studies and small-bowel biopsy. Common histologic findings include villous atrophy, loss of the normal villus architecture, intraepithelial lymphocytic infiltrates, and crypt hyperplasia. References: Celiac disease: diagnosis and management. (http://www.ncbi.nlm.nih.gov/pubmed/24444577) Evaluation of chronic diarrhea. (http://www.ncbi.nlm.nih.gov/pubmed/22085666)

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