GI - Malabsorption Syndromes; Inflammatory Bowel Disease

Question 1

What is the term for poor oxygenation to the intestines due to decreased/impeded blood flow?

Answer 1

Mesenteric ischemia

Question 2

Name a few levels of infarction severity of acute mesenteric ischemia.

Answer 2

Mucosal infarction;

mural infarction;

transmural infarction

Question 3

Describe the gross morphology of a case of transmural acute mesenteric ischemia.

Bowel:

Submucosa/subserosa:

Wall:

Lumen:

Answer 3

Bowel: dusky red, congested

Submucosa/subserosa: ecchymosis (skin discoloration due to bleeding underneath)

Wall: edematous, thick, hemorrhagic

Lumen: bloody (this is what presents clinically; patients come in with bloody stool)

Question 4

How does acute mesenteric ischemia present clinically?

Answer 4

Bloody stool

Question 5

Describe the microscopic morphology of acute mesenteric ischemia.

Answer 5

Mucosal necrosis/hemorrhage

Submucosal edema

Muscle layer is indistinct

Gangrene and perforation due to intestinal bacteria

Fibrin deposition

Question 6

Chronic mesenteric ischemia is caused by severe compromise of ___+ major arteries by ___________.

Answer 6

Chronic mesenteric ischemia is caused by severe compromise of 2+ major arteries by atherosclerosis.

Question 7

What are the lesions of chronic mesenteric ischemia situated?

Answer 7

Segmental and patchy

Question 8

Clinically, chronic mesenteric ischemia mimics what disorder?

Answer 8

Inflammatory bowel disease

Question 9

Most nutrient absorption occurs in what portion(s) of the intestines?

Answer 9

The duodenum and jejunum

Question 10

What substances are absorbed in the distal ileum only?

Answer 10

Bile salts;

B12

Question 11

__________ refers to poor transport/absorption of micronutrients that have already broken up.

__________ refers to incomplete breakdown of particles in the intestinal lumen.

Answer 11

Malabsorption refers to poor transport/absorption of micronutrients that have already broken up.

Maldigestion refers to incomplete breakdown of particles in the intestinal lumen.

Question 12

What is the most common cause of malabsorption disorders?

Answer 12

Absence of brush border enzymes

(e.g. lactase deficiency, post-viral enzyme deficiency, etc.)

Question 13

True/False.

Malabsorption has many potental causes, including: enzyme deficiencies, impaired mobility, secretory insufficiency (e.g. gallbladder or pancreatic issue), sprue, fibrosis, short-bowel syndrome.

Answer 13

True.

Question 14

Malabsorption with diarrhea is usually a result of impaired absorption of what?

Answer 14

Carbohydrates

Question 15

Malabsorption with steatorrhea is often a result of what?

Answer 15

Pancreatic insufficiency

Question 16

A mix of what three S/Sy are typically seen in malabsorptive disorders?

Answer 16

Diarrhea;

steatorrhea;

bloating

Question 17

What is the most important of the diagnostic tests malabsorption syndromes?

What does it differentiate?

Answer 17

The stool fecal fat test (Sudan stain);

osmotic diarrhea vs. true fat absorption issues

Question 18

What test can be used to check for pancreatic exocrine insufficiency?

Answer 18

The fecal pancreatic elastase test

Question 19

______ vitamin levels can be checked to assess a patient’s potential malabsorption.

Answer 19

Serum vitamin levels can be checked to assess a patient’s potential malabsorption.

Question 20

True/False.

Celiac disease is a wheat allergy.

Answer 20

False.

Celiac disease is a multifactorial autoimmune disorder triggered by the proteins in wheat, rye, barley, and sometimes oats.

Question 21

What genetic haplotype is most associated with Celiac disease?

Answer 21

HLA DQ2 and DQ8

Question 22

Celiac disease is a _________-mediated disorder that presents most severely in the __________ and _________ of the intestines.

Answer 22

Celiac disease is a T-cell-mediated disorder that presents most severely in the duodenum and jejunum of the intestines.

Question 23

In Celiac disease, T cells are targeting what?

Answer 23

Tissue transglutaminase

Question 24

Celiac disease leads to ___________ of the small intestinal villi and loss of the ______________.

Answer 24

Celiac disease leads to flattening of the small intestinal villi and loss of the microvilli brush border.

Question 25

Normally villous height should be _______ than crypt depth. This is inverted in celiac disease.

Answer 25

Normally villous height should be **_larger_** than crypt depth. This is inverted in celiac disease.

Question 26

Celiac disease is characterized by the presence of _____________ in the lamina propria.

Answer 26

Celiac disease is characterized by the presence of **_mononuclear cells_** ***(plasma cells, lymphocytes, macrophages, eosinophils, and mast cells)*** in the lamina propria.

Question 27

What antibodies are associated with Celiac disease?

Answer 27

Anti-**TTG**, anti-**endomysial** antibodies, **deamidated**-**gliadin** antibodies

Question 28

Will a patient with Celiac disease still have relevant serum antibodies if they stop eating gluten?

Answer 28

No.

Question 29

Tropical (post-infectious) sprue can affect what portion(s) of the intestines?

Answer 29

The entire small bowel

Question 30

**True/False**. Tropical (post-infectious) sprue almost always presents as severely flat lesions.

Answer 30

**False**. Tropical (post-infectious) sprue ***is variable and*** can present ***normally or*** as severe flat lesions.

Question 31

Tropical (post-infectious) sprue typically follows what geographic distribution?

Answer 31

**Caribbean** or **southeast** **Asia**

Question 32

How is tropical (post-infectious) sprue treated?

Answer 32

Antibiotics

Question 33

What term refers to a non-infectious over-colonization of the small intestine by normal gut flora?

Answer 33

Small intestine bacterial overgrowth | (SIBO)

Question 34

Name some potential causes of small intestine bacterial overgrowth (SIBO).

Answer 34

**Surgical resection**, multiple **diverticula**, **stasis**, blind-loop syndrome

Question 35

Small intestine bacterial overgrowth (SIBO) is characterized by __________ inclusions.

Answer 35

Small intestine bacterial overgrowth (SIBO) is characterized by **_neutrophilic_** inclusions.

Question 36

Whipple's disease (an extremely rare form of malabsorption syndrome) is of what etiology?

Answer 36

***Tropheryma whipplei*** | (WD is a systemic bacterial infection.)

Question 37

Name some of the S/Sy associated with Whipple's disease.

Answer 37

Fever, malabsorption, weight loss, lymphadenopathy

Question 38

What are the **CAN** effects associated with Whipple's disease?

Answer 38

**C**ardiac effects **A**rthralgias **N**eurologic effects

Question 39

Describe the histology of Whipple's disease.

Answer 39

Organism-laden **macrophages** building up in the **lamina** **propria**; **PAS**-positive granules within macrophages

Question 40

Describe the Gram-stain and shape of *Trophyerma whippli*.

Answer 40

Gram-positive bacilli

Question 41

What are the two main forms of irritable bowel disease?

Answer 41

Ulcerative colitis + Crohn's disease

Question 42

Crohn’s disease is a chronic inflammatory disease of __________ etiology that can affect any part of the GI tract and occasionally other organs, but usually affects the __________ and \_\_\_\_\_\_\_\_\_\_.

Answer 42

Crohn’s disease is a chronic inflammatory disease of **_idiopathic_** etiology that can affect any part of the GI tract and occasionally other organs, but usually affects the **_distal ileum_** and **_proximal colon_**.

Question 43

How do Crohn's disease lesions appear?

Answer 43

**Transmural, discontinuous ('skip') lesions** *(with _thickening_, _cobblestoning_, _fistulas_, _fibrosis_, and _non-caseating_ _granulomas_)*

Question 44

Ulcerative colitis is a chronic inflammatory disease of __________ etiology affecting primarily the _______ (layer(s)) of the _______ (intestinal section(s)).

Answer 44

Ulcerative colitis is a chronic inflammatory disease of **_idiopathic_** etiology affecting primarily the **_mucosa_** of the **_colon_**.

Question 45

How do the lesions of ulcerative colitis appear?

Answer 45

**Superficial, mucosal lesions that are diffuse & contiguous​** (and flattened mucosa stemming from the rectum)

Question 46

Inflammatory pseudopolyps are sometimes associated with which form of inflammatory bowel disease?

Answer 46

Ulcerative colitis

Question 47

In ulcerative colitis, the bowel wall is _______ (thickened/thinned). In Crohn's disease, the bowel wall is _______ (thickened/thinned).

Answer 47

In ulcerative colitis, the bowel wall is **_thinned_**. In Crohn's disease, the bowel wall is **_thickened_**.

Question 48

In ulcerative colitis, the inflammation is _______ (mucosal/submucosal/transmural). In Crohn's disease, the inflammation is _______ (mucosal/submucosal/transmural).

Answer 48

In ulcerative colitis, the inflammation is **_mucosal_**. In Crohn's disease, the inflammation is **_transmural_**.

Question 49

In ulcerative colitis, the fibrosis is _______ (mild/marked). In Crohn's disease, the fibrosis is _______ (mild/marked).

Answer 49

In ulcerative colitis, the fibrosis is **_mild_**. In Crohn's disease, the fibrosis is **_marked_**.

Question 50

Which form of inflammatory bowel disease is associated with non-caseating granulomas?

Answer 50

Crohn's disease (50% of cases)

Question 51

Which form of inflammatory bowel disease is associated with fistulas and deep, linear ulcers?

Answer 51

Crohn's disease

Question 52

Which form of inflammatory bowel disease is most associated with superficial ulcerations only?

Answer 52

Ulcerative colitis

Question 53

How does Crohn's disease typically present clinically?

Answer 53

**Pain**, **diarrhea**, **perianal** **disease**, obstruction, fistulas, strictures

Question 54

How does ulcerative colitis typically present clinically?

Answer 54

**Bloody diarrhea,** strictures, toxic colitis

Question 55

Which inflammatory bowel disease is associated with systemic complications?

Answer 55

**Both** Crohn's disease and ulcerative colitis

Question 56

Which inflammatory bowel disease is associated with strictures, dysplasia, and carcinoma?

Answer 56

**Both** ulcerative colitis and Crohn's disease

Question 57

The longer the _________ of either Crohn's disease or ulcerative colitis, the higher the incidence of associated malignancy.

Answer 57

The longer the **_duration_** of either Crohn's disease or ulcerative colitis, the higher the incidence of associated malignancy.

Question 58

_Describe the following colorectal malignancies:_ ## Footnote **Colonic** – **Mucinous** – **Signet** **ring** –

Answer 58

_Describe the following colorectal malignancies:_ ## Footnote **Colonic** – **_flat ulcers_** **Mucinous** – **_tumor cells floating in mucus_** **Signet** **ring** – **_mucin-filled signet ring cells, but remember these also come up in Lynch syndrome_**