GI Nutrition, Absorption, and Motility 2 — Questions and Answers
Question 1: Gastroparesis is most commonly associated with which systemic disease in US clinical practice?
- Hypothyroidism
- Diabetes mellitus (Correct answer)
- Systemic lupus erythematosus
- Rheumatoid arthritis
Correct answer: Diabetes mellitus
Diabetic autonomic neuropathy is the most common identifiable cause of gastroparesis, causing delayed gastric emptying due to vagal nerve dysfunction.
Question 2: The gold standard test for diagnosing gastroparesis is:
- Upper GI series (barium swallow)
- Gastric emptying scintigraphy (nuclear medicine scan) (Correct answer)
- Wireless motility capsule
- CT abdomen with contrast
Correct answer: Gastric emptying scintigraphy (nuclear medicine scan)
Gastric emptying scintigraphy using a standardized radiolabeled solid meal (e.g., Tc-99m sulfur colloid egg meal) is the diagnostic gold standard for gastroparesis.
Question 3: Total parenteral nutrition (TPN) is indicated when patients cannot tolerate enteral nutrition; which of the following is a known complication of long-term TPN?
- Hyperalbuminemia
- Intestinal-failure-associated liver disease (IFALD) (Correct answer)
- Hypokalemia resistant to supplementation
- Hypoglycemia unresponsive to dextrose
Correct answer: Intestinal-failure-associated liver disease (IFALD)
Long-term TPN bypasses the gut and can cause intestinal atrophy and intestinal-failure–associated liver disease (formerly TPN-associated cholestasis/cirrhosis).
Question 4: Dumping syndrome after gastric surgery is classified as early or late; late dumping (1–3 hours postprandially) is caused by:
- Rapid fluid shifts into the intestinal lumen causing hypotension
- Reactive hypoglycemia from excessive insulin release (Correct answer)
- Bacterial overgrowth in the gastric remnant
- Bile reflux into the esophagus
Correct answer: Reactive hypoglycemia from excessive insulin release
Late dumping is caused by rapid carbohydrate absorption triggering excessive insulin secretion, leading to reactive hypoglycemia 1–3 hours after eating.
Question 5: Which vitamin deficiency classically results from fat malabsorption and causes night blindness and xerophthalmia?
- Vitamin B1 (thiamine)
- Vitamin C (ascorbic acid)
- Vitamin A (retinol) (Correct answer)
- Vitamin B12 (cobalamin)
Correct answer: Vitamin A (retinol)
Vitamin A deficiency, common in fat malabsorption states, impairs rhodopsin regeneration in rod cells, causing night blindness and keratinization of the cornea (xerophthalmia).
Question 6: Enteral nutrition is preferred over TPN whenever possible due to all of the following EXCEPT:
- Maintains intestinal mucosal integrity
- Reduces infectious complications
- Preserves gut microbiome diversity
- More convenient for outpatient administration (Correct answer)
Correct answer: More convenient for outpatient administration
TPN bags are typically administered at home or hospital via central lines on a scheduled infusion, whereas enteral feeding requires tube placement and pump management — neither is clearly more convenient.
GI Nutrition, Absorption, and Motility 2
Gastroparesis is most commonly associated with which systemic disease in US clinical practice?