10 free ABIM GI practice questions in the real exam format, covering the official content areas, with an explanation for every answer.
ABIM GI Practice Test 3Tutor mode
Question 1 of 10
Other Disorders
A 52-year-old woman is evaluated for 4 months of watery diarrhea, five or six stools daily, that stops when she fasts for 48 hours. She takes an over-the-counter "digestive health" supplement, a calcium–magnesium product and a multivitamin. She has no weight loss or nocturnal stools. Colonoscopy with random biopsies, celiac serology and stool pathogen tests are normal. A 48-hour stool collection shows a daily volume of 650 g. Stool results are shown. Which of the following is the most likely cause of her diarrhea?
Stool water studies
Test
Result
Sodium
30 mEq/L
Potassium
25 mEq/L
Measured osmolality
296 mOsm/kg
pH
7.1
Calculate the osmotic gap using an assumed stool osmolality of 290 mOsm/kg.