OnlineMedEd: Gastroenterology - "Chronic Diarrhea"

Question 1

What is the calculated osms?

Answer 1

2 x sodium + potassium

Question 2

Nocturnal symptoms are most common in which type of diarrhea?

Answer 2

Secretory

In secretory diarrhea, the primary problem is that the colonic mucosa is aberrantly secreting water. This happens regardless of activity or food intake, so secretory diarrhea causes nighttime diarrhea.

Question 3

How do you use measured/calculated osms to determine osmolar diarrhea?

Answer 3

You measure the osms and calculate the osms of the stool If the gap between the two is greater than 100, then it is osmolar.

For example:
•Measured osms (all the osms in the stool) = 290
•Calculated osms (sodium and potassium x 2) = 150
•Difference = 140 (this is the extra molecule that is inducing osmolar diarrhea)

Question 4

What are the causes of secretory diarrhea?

Answer 4

• Hormone-secreting tumors (e.g., VIPoma, carcinoid syndrome, Zollinger Ellison syndrome)
• Infectious (C. diff, V. cholerae)

Question 5

If you’re trying to rule out a gastrinoma and the patient’s gastrin levels are in the indeterminate range (250-1600), then you can _______________.

Answer 5

do a secretin stimulation test

Question 6

What complication can gastrinomas cause?

Answer 6

Gastric adenocarcinoma

The gastrinoma itself is usually not malignant, but the constant stimulation of the gastric tissue can cause malignant transformation of the stomach.

Question 7

Carcinoid tumors secrete ___________.

Answer 7

serotonin

Question 8

Serotonin is bad for the ______________.

Answer 8

heart valves (look for right-sided heart failure)