Colon

Question 1

Mg vs. Calcium antacids

Answer 1

Mg antacids- cause movements (diarrhea). Calcium antacids- cause constipation

Question 2

What if patient is hemoccult + and complains of rectal bleeding-

Answer 2

refer to colonoscopy

Question 3

What if patient is 45 or older with positive hemoccult test but denies rectal bleeding-

Answer 3

refer for colonscopy, and give trial of fiber supplementation

Question 4

What are studies of pelvic floor function

Answer 4

balloon expulsion test, defacography, anorectal manometry

Question 5

Diagnostic studies for constipation

Answer 5

Colon transit study and studies of pelvic floor function

Question 6

Tx for constipation- general

Answer 6

minimize constipation causing meds, lifestyle changes, treat hypothyroidism, treat diabetes, increase fluid and fiber intake, regular exercise

Question 7

pharmacologic therapy for constipation

Answer 7

ONSES- osmotic laxatives (mag citrate), non-absorbable sugars, saline laxatives (MOM), emollient laxatives, stimulant laxatives

Question 8

What is a consequence of excessive stimulant laxative use in tx of constipation?

Answer 8

melanosis coli- inner lining of colon turning brown

Question 9

Rescue meds for acute constipation tx

Answer 9

stimulant and osmotic laxatives, and enemas (avoid soap studs)

Question 10

tx of fecal impaction

Answer 10

manual disimpaction

Question 11

Colonic pseudoobstruction and dilation of colon seen in..

Answer 11

Ogilve’s syndrome

Question 12

Cause of ogilve’s syndrome related to..

Answer 12

electrolyte abnormalities

Question 13

Tx of ogilve’s syndrome

Answer 13

bowel rest, IVF, electrolyte replacement

Question 14

cause of diverticulosis

Answer 14

pulsion, d/t increased colonic pressure

Question 15

What part of colon is spared in diverticulosis?

Answer 15

Rectum spared

Question 16

pathogenesis of diverticulosis

Answer 16

1. Hypermotility- high colonic pressure, affects mostly sigmoid colon. 2. Simple massed diverticulosis- occurs throughout colon, d/t weak muscular wall from CT disorder like Marfan’s or Ehlers-Danlos

Question 17

complications from diverticulosis

Answer 17

bleeding and infection(diverticulitis)

Question 18

tx of uncomplicated diverticulosis

Answer 18

high fiber diet

Question 19

Which diagnostic imaging tests are contraindicated in acute diverticulitis?

Answer 19

Barium enema and colonoscopy

Question 20

Patient presents with colicky abdominal pain, severe pain in LLQ, constipation, diarrhea, pain relieved by defecation, N/V, abdominal distension. Also see colovesical fistula. Dx?

Answer 20

Probably diverticulitis

Question 21

What is colovesical fistula?

Answer 21

most common type of fistula from colon to bladder in diverticulitis

Question 22

Tx of diverticulitis

Answer 22

outpatient abx or IV hospitalize if necessary

Question 23

Should you perform colonoscopy in diverticulitis?

Answer 23

NO. Wait 6-8 weeks after resolution to perform to r/o cancer

Question 24

After 3-4 episodes of diverticulitis…consider

Answer 24

elective colectomy

Question 25

When would you need to emergently perform surgery in diverticulitis

Answer 25

If free perforation, causing pneumoperitoneium and fecal peritonitis. Surgery involves removal of colon and formation of an ostomy (Hartman procedure). Takedown ostomy in 2-3 months and bowel is reconnected

Question 26

Hartman procedure

Answer 26

removal of rectosigmoid colon and formation of ostomy- surgery used in colon cancer and complicated diverticulitis

Question 27

Ischemic colitis cause

Answer 27

mesenteric vascular occlusion (inferior mesenteric artery often)

Question 28

Patient presents with LUQ abdominal pain, bloody diarrhea. Is hypotensive and dehydrated. You suspect..

Answer 28

Ischemic colitis

Question 29

Watershed area

Answer 29

areas perfused by 2 arteries- splenix flexure in colon - this is why ischemic colitis usually presents with LUQ pain

Question 30

ischemic colitis- how do diagnose?

Answer 30

colonscopy

Question 31

Patient presents with RUQ pain, fever, watery or bloody diarrhea, distenstion, nausea. Areas most affected are right colon, including cecum. You suspect..

Answer 31

Neutropenic colitis or typhlitis

Question 32

Diarrhea in toxic megacolon can either by bloody or no movement- why?

Answer 32

if bloody diarrhea- early toxic megacolon. if no movement- late due to lack of contractility.

Question 33

Most common causes of toxic megacolon

Answer 33

C. Diff colitis, or U. Colitis

Question 34

C. Difficile infection often follows...

Answer 34

antibiotic use

Question 35

What does C. difficile cause

Answer 35

pseudomembraneous colitis (accordion sign). also a cause of gastritis and peptic ulcers

Question 36

"Accordion sign" -

Answer 36

Pseudomembranous colitis (caused by C. diff)

Question 37

Tx of c diff infection

Answer 37

oral and IV abs

Question 38

tx for toxic megacolon

Answer 38

surgery

Question 39

Xray finding characteristic of colon cancer

Answer 39

apple core lesion

Question 40

95% of colon cancers are...

Answer 40

adenocarcinomas

Question 41

3-4% of patients with colorectal cancer have a genetic susceptibility syndrome, like...

Answer 41

HNPCC or FAP (autosomal dominant, highly penetrated)

Question 42

hereditary polyposis diseases

Answer 42

Juvenile polyposis, Peutz-Jegher's syndrome, HNPCC, FAP

Question 43

4 types of juvenile polyposis

Answer 43

Juvenile polyposis syndrome, Cronkhite-Canada syndrome, Bannayan-Riley-Ruvalcaba syndrome, and Cowden disease

Question 44

Extracolinic manifestations in juvenile polyposis syndrome

Answer 44

None

Question 45

manifestations besides polyps in colon in cronkhite-canada syndrome

Answer 45

ectodermal lesions

Question 46

manifestations besides polyps in colon in bannayan RR syndrome

Answer 46

macrocephaly and genital hyperpigmentation

Question 47

manifestations besides polyps in Cowden disease

Answer 47

facial trichilemmomas, thyroid goiter, and cancer, breast cancer

Question 48

mode of inheritance in Peutz-Jeher's syndrome

Answer 48

autosomal dominant

Question 49

Peutz Jegher's syndrome characterized by...

Answer 49

multiple hamartomatous polyps and melanotic pigmentation of the skin, lips, and gums. Lifetime risk of colorectal cancer

Question 50

Difference in R vs. L sided tumors in colon cancers in Stools

Answer 50

R sided tumors present with bleeding- stool on R is liquid. L sided tumor stools are solid and cause obstruction (alternating constipation and diarrhea)

Question 51

How fast does colon cancer spread?

Answer 51

Doubling time is 130 days. Takes 5 years to produce tumor large enough to produce any symptoms. Slow growing!

Question 52

Persistent rectal bleeding in patient

Answer 52

workup for colon cancer!

Question 53

Steps in diagnosis of colon cancer

Answer 53

Hx of unrelenting rectal bleeding or abdominal pain in patient, Hemoccult positive- order colonoscopy. One diagnosis is made, CT scans of chest, abdomen, and pelvis to stage disease

Question 54

CEA

Answer 54

Carcinoembryonic angigen- useful in detecting recurrences of colon cancer after resection, but not specific

Question 55

complications of colon cancer

Answer 55

obstruction, perforation, and direct extension

Question 56

tx of colon cancer

Answer 56

partial colectomy usually with anastomosis- laparoscopic or open

Question 57

Primary vs. metastatic colon cancer tx

Answer 57

primary- chemo agents, antimetabolites. Metastatic- (MAb to VEGF)- Bevacizumab, Topoisomerase I inhibition (irinotecan), MAb to EGFR- cetuximab

Question 58

adjuvant vs. neoadjuvant

Answer 58

adjuvant- meds given AFTER sx. neoadjuvant- meds given BEFORE sx - to make tumor smaller for surgery

Question 59

F/U with colon cancer colonoscopy

Answer 59

colonoscopy 3 months after emergency resection. And then every 1-3 years for screening.