Diseases of the Small Bowel

Question 1

The longest part of the small intestine is the _____________.

Answer 1

ileum (55%)

Question 2

The surface area of the small intestines is amplified _______-fold by the plicae circulares, villi, and microvilli.

Answer 2

600

Question 3

What are the signs/symptoms/sequelae of malabsorption?

Answer 3

Weight loss, diarrhea, steatorrhea, and vitamin deficiencies

Question 4

There are a lot of causes of malabsorption. List the categories and some examples of each.

Answer 4

Surgery: gastric bypass or small-bowel resection

Bacterial overgrowth

Medications: cholestyramine, phenytoin, folate

Flattened villi: celiac or tropical sprue

Pancreatic insufficiency

Ischemia

Liver disease: failure to produce bile or biliary obstruction

Question 5

True or false: a normal fecal sample will stain for some fat on Sudan staining.

Answer 5

True. The droplets will be smaller.

Question 6

True or false: pancreatic insufficiency is an early symptom of pancreas dysfunction.

Answer 6

False. Insufficiency only occurs when 90% of the pancreas is destroyed.

Question 7

Which nutrient category is the first to be defective in pancreatic insufficiency? The last?

Answer 7

First: fat
Second: protein
Last: carbohydrate (rare, because of the availability of salivary amylase)

Question 8

Liver disease and bile-duct obstruction can lead to _________.

Answer 8

decreased bile and subsequent inability to form bilious micelles

Question 9

Gastric-bypass patients should be given _______________.

Answer 9

multivitamins, to avoid deficiencies in B12, C, Ca, and D

Question 10

The concentration of bacteria generally _____________ as you go down the GI tract.

Answer 10

increases

Question 11

Small-intestinal bacterial overgrowth (SIBO) is defined as bacteria concentration greater than ______.

Answer 11

10^5/mL

Question 12

What causes SIBO?

Answer 12

Diverticula 
Hypomotility 
Partial obstruction
Decreased acid secretion
Enterocolonic fistula

Question 13

Which antibiotic is best for SIBO?

Answer 13

Ciprofloxacin

Question 14

High folate levels can indicate ____________.

Answer 14

SIBO, because bacteria produce it and then it gets absorbed by the small intestine

Question 15

Review the fat-soluble vitamins and the symptoms of their deficiencies.

Answer 15

A: night blindness
D: osteomalacia
E: hemolytic anemia
K: clotting disorders

Question 16

What immunoglobulin will be present in someone with the disorder that results in loss of villi, hyperplasia of the small intestinal crypts, and lymphocyte proliferation?

Answer 16

IgA tissue-transglutaminase (this being celiac)

Question 17

One slice of bread contains 5 grams of gluten, and those with celiac only need ______ per day to have histologic changes.

Answer 17

50 mg

Question 18

IgA deposits in the epidermal grooves will appear in which GI disorder?

Answer 18

Celiac (the rash is called dermatitis herpetiformis and is almost pathognomonic for celiac)

Question 19

Celiac is more common in ____________.

Answer 19

• females (2:1)
• those with autoimmune diseases
• HLA-DQ2 and HLA-DQ8 (100% of those with celiac have one of these, but not everyone with these phenotypes will develop celiac)
• …

Question 20

Describe the presentation of tropical sprue.

Answer 20

Aerobic coliform bacteria cause flattening of villi (similar to celiac) and subsequent megaloblastic anemia from cobalamin and folate deficiency. It is only found in those who live in or have recently visited the tropics. Treat with long-term folate and cobalamin supplementation.

Question 21

Whipple’s disease results from ______________.

Answer 21

infection with the Gram-positive actinomycete Tropheryma whippelii; macrophages will stain positive for PAS inclusions

Question 22

The vasculature of the __________ has redundancies, so multiple vessels or the branching point of lots of vessels must be occluded to develop symptoms.

Answer 22

mesentery

Question 23

True or false: small-intestine tumors are common.

Answer 23

False. The incidence is roughly 1 / 100,000.

Question 24

Watery diarrhea indicates _______________.

Answer 24

osmotic or secretory diarrhea

Question 25

Watery, osmotic diarrhea can result from _____________.

Answer 25

lactose intolerance, excess undigested sorbitol, or fructose consumption (all of which lead to a hypertonic state in the large intestine)

Question 26

The stool sample test that distinguishes secretory and osmotic diarrhea is ________________.

Answer 26

Stool osmolarity anion gap:

290 - 2(Na + K)

If it is greater than 50 mOsm, then the diarrhea is osmotic. If it is less than 50 mOsm, then it is secretory.

Question 27

The ____________ is the only site of bile reabsorption.

Answer 27

ileum

Question 28

The gold-standard diagnostic tool for inflammatory bowel disease is ____________.

Answer 28

endoscopy

Question 29

The most common cause of pancreatic insufficiency is _____________.

Answer 29

chronic pancreatitis

Question 30

What antibody, other than IgA-TTG, indicates celiac?

Answer 30

Anti-endomysial antibodies

Question 31

Transmural necrosis indicates ischemia from what cause?

Answer 31

Thrombosis, whereas chronic presents with mucosal necrosis

Question 32

Ischemia presents with _____________ pain.

Answer 32

post-prandial

Question 33

Metastasis of carcinoid tumors to the ___________ causes carcinoid syndrome.

Answer 33

liver

Question 34

The appendix averages ____ centimeters.

Answer 34

9

Question 35

Cobblestoning of the small intestine is also called ___________.

Answer 35

scalloping

Question 36

Celiac causes which kind of cancer?

Answer 36

T-cell lymphoma

Question 37

What serum test can you run on a patient with selective IgA deficiency if you are suspicious of celiac?

Answer 37

Anti-gliadin IgG

Question 38

Lactose intolerance leads to ____________ diarrhea.

Answer 38

osmotic