Tufts OpenCourseware
Author: Laurence Scott Bailen, M.D.

1. Question 1

A 25 year-old man comes to your office complaining of frequent bloating, gas, and diarrhea. His diarrhea is non-bloody and he has no associated fevers nor has he lost weight. Stool specimens checked for various infectious organisms all return negative. He notes that his symptoms typically occur shortly after eating ice cream or cheese pizza. You check stool sodium and potassium concentration and calculate the fecal osmotic gap.

Which of the following results for the fecal osmotic gap would you most likely find in this patient?

  1. 75 mosm/kg H20

  2. 25 mosm/kg H20

  3. 140 mosm/kg H20

  4. 55 mosm/kg H20

  5. 100 mosm/kg H20

For questions #2 and #3, match the most likely cause of diarrhea from the list below.

2. Question 2

A 35 year-old Irish woman with bloating, diarrhea typically after eating, and weight loss comes in. She has an unusual blistering skin rash. Blood tests show that she has an iron-deficiency anemia.

3. Question 3

A 46 year-old man has had non-bloody diarrhea for more than one year. He also has epigastric abdominal pain which prompted an upper endoscopy. This revealed erosive esophagitis and several gastric and duodenal ulcers, some in the second portion of the duodenum.

  1. Laxative abuse

  2. Chronic pancreatitis

  3. Crohn’s disease

  4. Bile acid malabsorption

  5. Celiac sprue

  6. Ischemic colitis

  7. Carcinoid syndrome

  8. Zollinger-Ellison syndrome

  9. Hyperthyroidism

  10. Irritable bowel syndrome

  11. Ulcerative colitis

  12. Amebiasis