small intestine

Question 1

causes for duodenal ulcers

Answer 1

H. pylori (90%)

Zollinger-Ellison Syndrome (gastrinoma in pancreas): consider if RECURRENT after tx with PPI, check gastrin level

Question 2

BILIOUS vomiting

“double bubble sign”

Answer 2

duodenal atresia (no canalazation of duodenum = blind pouch)
distention of stomach in front of pylorus + distention of duodenum pouch

Question 3

associated with duodenal atresia

Answer 3

down syndrome

Question 4

imaging evaluation of patient with jaundice

Answer 4

endoscopic retrograde cholangiopancreatogram (ERCP)

esophagus → stomach → duodeunum → inject dye in ampulla of vater → visualize biliary tree + pancreatic duct

Question 5

located in duodenal submucosa

Answer 5

brunner gland

Question 6

hypertrophied with duodenal ulcers

Answer 6

brunner glands

Question 7

prokinetic agents

Answer 7

↑Ach (parasympathetic), ↑5HT (carcinoid syndrome - produces vasoactive amines), ↓D2
cholinergic agoinst (bethanechol)
acetylcholinesterase inhibitors (neostigmine)
metoclopromide: stimulate 5HT4, inhibit D2
macrolide: stimulate smooth muscle motilin receptors

Question 8

no peristalsis - blood diverted to more important areas of body

cause: post-op, stroke, septic shock, ICU
treatment: prokinetic agents

Answer 8

intestinal ileus

Question 9

↑ 5HT causes

Answer 9

diarrhea (seen in carcinoid syndrome)

Question 10

enterocyte characteristics

Answer 10

villi: absorption

secrete digestive enzymes

Question 11

Crypts of Lieberkuhn

Answer 11

between villi of enterocytes

glands that secrete digestive enzymes

Question 12

iron absorption

Answer 12

duodenum

Question 13

folate absorption

Answer 13

duodenum + jejunum

Question 14

B12 absorption

Answer 14

terminal ileum

Question 15

iron deficiency anemia due to malabsorption

Answer 15

antacids, some antibiotics (quinolones, tetracycline): iron absorption occurs in acidic environment
gastric bypass surgery: bypass duodenum

Question 16

causes of folate deficiency

Answer 16

poor nutrition: alcoholism

infant fed exclusively goat’s milk

Question 17

infant fed exclusively with goat’s milk

Answer 17

folate deficiency

Question 18

cause of B12 deficiency (megaloblastic anemia)

Answer 18

no terminal ileum
malnutrition
↓ absorption in terminal ileum
pernicious anemia: autoimmune destruction of gastric parietal cells (no IF)

Question 19

AR
lack of apo-B leading to defective chylomicron assembly → chylomicron doesn’t leave enterocyte → enterocytes stop fat absorption

Answer 19

abetalipoproteinemia

Question 20

apo-B48 is marker on chylomicrons

Answer 20

allows chylomicron to leave enterocyte

Question 21

steatorrhea (malabsorption of ADEK) failure to thrive (first few months of life)
ataxia
acanthocytes: star RBCs

Answer 21

abetalipoproteinemia

Question 22

disaccharidase deficiency
lactase breaks lactose → glucose + galactose
when not broken down: lactose is metabolized by bacteria in colon → fermentation →
bloating
cramping
diarrhea

Answer 22

lactase deficiency

Question 23

lactase located in tips of microvilli - can be damaged in

Answer 23

gastroenteritis - blunts microvilli

temporary lactase deficiency

Question 24

likely infectious cause

affects ENTIRE small intestine (vs celiac disease only in proximal small bowel)

Answer 24

tropical sprue

Question 25

complications of tropical sprue

Answer 25

vitamin deficiencies | megaloblastic anemia

Question 26

treatment of tropical sprue

Answer 26

antibiotics (doesn't improve with gluten-free diet)

Question 27

caused by tropheryma whipplei (G+)

Answer 27

whipple disease

Question 28

``` older white male: weight loss diarrhea fever LAD hyperpigmentation cardiac sx arthritis neruo sx ```

Answer 28

whipple disease

Question 29

PAS + foamy macrophages in intestinal lamina propria

Answer 29

whipple disease (t. whipplei inside macrophages)

Question 30

treatment of whipple disease

Answer 30

penicillin, ampicillin, tetracycline | 1-2 year long

Question 31

``` nausea bloating vomiting diarrhea malabsorption aspirate of jejunum: excessive bacterial growth ```

Answer 31

bacterial overgrowth of small intestine

Question 32

risk factor for bacterial overgrowth

Answer 32

``` dysmotility fistula diverticula illeocecal valve resection gastroenteritis PPIs ```

Question 33

``` complication of: chronic pancreatitis cystic fibrosis gallstones cancer ```

Answer 33

pancreatic insufficiency

Question 34

steatorrhea (fat malabsorption - ADEK vitamines)

Answer 34

pancreatic insufficiency

Question 35

small intestinal mucosa laden with distended macrophages in lamina propria

Answer 35

whipple disease

Question 36

defect in chylomicron exportation

Answer 36

abetalipoproteinemia

Question 37

chronic abdominal pain + altered bowel habits ab pain: crampy, variable intensity, IMPROVES with defecation bowel habits: diarrhea, constipation, alternating diarrhea and constipation other GI sx: GERD, dysphagia, early satiety, nausea, chest pain non-GI sx: urinary frequency/urgency, dysmenorrhea, dsypareunia, fibromyalgia (depression too)

Answer 37

irritable bowel syndrome

Question 38

symptoms NOT associated with IBS!!

Answer 38

``` rectal bleeding nocturnal ab pain weight loss anemia elevated inflammatory markers electrolyte abnormalities ```

Question 39

treatment of IBS

Answer 39

``` avoid lactose or gluten fiber supplement antispasmodics: dicyclomine, hyoscyamine antidepressants: TCA, SSRI guanylate cyclase agonist: IBS with constipation ```

Question 40

most common congenital anomoly in GI tract

Answer 40

Meckel diverticulum

Question 41

incomplete obliteration vitelline duct

Answer 41

Meckel diverticulum

Answer 42

Meckel diverticulum

Question 43

diagnosis of Meckel diverticulum

Answer 43

Meckel scan: look for ectopic gastric mucosa (pancreatic epithelium may also be present)

Question 44

most common abdominal emergency in kids

Answer 44

intussusception

Question 45

telescoping of bowel into DISTAL segment (near ileocecal junction - small bowel into cecum)

Answer 45

intussusception

Question 46

complications of: adenovirus Meckel diverticulum

Answer 46

intussusception (but usually idiopathic)

Question 47

"currant jelly" stool

Answer 47

intussusception (bloody stool)

Question 48

"bulls-eye" or "coil spring" on US

Answer 48

intussusception

Question 49

common causes of small bowel obstruction

Answer 49

``` ABC Adhesions: surgical adhesions from previous surgery (75%) Bulge: hernia (second most common - inguinal hernia incarcerated (can't reduce) → infarction/strangulation) Cancer: tumors (metastatic colorectal cancer most common) less common: volvulus intussusception chron's disease gallstone - obstructs lumen of SB ileus bezoar bowel wall hematoma from trauma inflammatory stricture congenital malformation radiation enteritis ```

Question 50

dilated bowel on ab xray

Answer 50

small bowel obstruction | gas builds up

Question 51

> 3 days to pass meconium

Answer 51

meconium ileus

Question 52

normal time that meconium is passed

Answer 52

within 3 days of birth

Question 53

causes of meconium ileus

Answer 53

cystic fibrosis | hirschsprung disease

Question 54

``` premature infant that received oral feeds too soon: bowel undergoes feeding intolerance ↑gastric residuals ab distention bloody stools perforation ```

Answer 54

necrotizing enterocolitis

Question 55

abdominal xray shows: dilated loops of bowel paucity of gas pneumatosis intestinalis (presence of gas in wall of intestine)

Answer 55

necrotizing enterocolitis

Question 56

treatment of necrotizing enterocolitis

Answer 56

bowel rest by giving parental nutrition (IV food)

Question 57

↓ blood flow to part of bowel associated with atherosclerosis of celiac or mesentaric arteries splenic flexure (watershed) is susceptible to injury distal colon too

Answer 57

ischemic colitis

Question 58

elderly pain out of proportion to physical exam (no signs of appendicitis, cholecystitis) WORSE with eating weight loss

Answer 58

ischemic colitis

Question 59

small vascular malformation in gut → bleed easily common in elderly usually cecum or ascending colon unexplained GI bleeding + anemia dx: colonoscopy to see bleeding, angiography will better show bleeding

Answer 59

angiodysplasia

Question 60

neuroendocrine tumor that secretes SEROTONIN in appendix, ileum, rectum and lung

Answer 60

carcinoid syndrome

Question 61

``` BFDR Bronchospasm Flushing Diarrhea Right sided murmur (deposits in R sided valves) + edema, ascites (all = Right sided heart disease) ```

Answer 61

carcinoid syndrome: cause by excess serotonin from carcinoid tumor *symptoms only if tumor is outside of GI tract because liver metabolizes all the 5HT produced in colon (carcinoid tumor mets outside of GI or started in lung)