diverticulosis/itis and colon cancer Flashcards
presence of small mucosal pockets in the colon
diverticulosis
diverticulosis is common in western countries due to
lack of fiber in diet
describe the colonic distribution of diverticulosis
- 95% involve sigmoid (most common)
- 65% isolated to sigmoid
diverticulosis often presents as
- most often asymptomatic
- coincidental finding on imaging study or colonoscopy
- occasional abd cramping, diarrhea, constipation, bloating
List the two main complications of diverticulosis
- diverticulitis 15-25%
- bleeding 5-15%
differentiate between two types of diverticulitis
- simple (75% of cases)
- complicated (35% of cases)
- abscess
- osbstruction
- perforation
- fistula
tx of asymptomatic diverticulosis
-
high fiber diet (20-35 g/d)
- increases stool bulk reducing work of colon for bowel movement
- adequate fluid hydration
define diverticulitis
- an acute symptomatic episode corresponding to inflammation of a diverticula
how does diverticulosis develop into diverticulitis
- fecal material obstructs neck of diverticulum or increased luminal pressure results in erosion of diverticular wall -> inflammation -> focal necrosis -> perforation
macroperforation caused by diverticulitis can lead to
- free air
- peritonitis
clinical presentation
- progressive steady/aching LLQ pain
- N/V (20-62%)
- constipation (50%)
- diarrhea (25-35%)
- urinary symptoms (10-15%)
diverticulitis
when you see urinary symptoms in diverticulitis, what must you rule out
- signs of colovesicular fistula
if patient presents with LLQ pain, what is an important question to ask them
prior h/o diverticulitis
What is the common clinical presentation of peritonitis
- rigid abdomen with guarding
- rebound tenderness
- absent bowel sounds
lab studies to evaluate diverticulitis
- CBC, CMP
- stool for occult blood
- UA
- stool cultures if diarrhea
- urine pregnancy
What is the test of choice for acute diverticulitis
- CT scan with contrast
what tests are contraindicated in acute diverticulitis
- flexible sigmoidoscopy
- colonoscopy
- barium enema
**all increase risk of perforation
tx of uncomplicated diverticulitis
- abx: choose gram negative/anaerobic coverage x 10-14 days
- Ex: metronidazole (flagyl) AND ciprofloxacin
managment of diverticulitis following acute episode
- long term daily fiber intake
- colonscopy 4-6 weeks following acute episode to r/o colon CA
Describe the bleeding that occurs in 15% of patients with diverticulosis
-
painless bleeding
- not an inflammatory process
- can be large in volume
- usually resolves spontaneously (75%)
inpatient management of diverticulitis
- IV abx therapy (gram negative and anaerobes)
- transition to PO abx when pain improves, continue for 10-14 d
- colonoscopy 4-6 weeks following acute attack
- fiber supplementation
diverticular bleeding usually occurs on what side of the colon
-
Rt side (50-90%)
- diverticulum are wider and have more exposure of vasa recta
management of diverticular bleeding
- large volume -> hospitalize, transfusion?
- locate source of bleeding
- EGD/ NG gastric lavage (r/o UGI source)
- Flex seg or colonoscopy
- RBC scan
What are hyperplastic polyps
- non-neoplastic
- benign
What are pseudopolyps
- non-neoplastic
- inflammatory/IBD
List the three types of colon adenomas (polyps)
- tubular adenoma
- tubulovillous adenoma
- villous adenoma
which type of colon adenomas (polyps) is the most common
tubular adenoma
which type of colon adenomas (polyps) has the highest cancer risk
villous adenoma
almost all colorectal cancers develop from . What is the time frame?
-
adenomas
- <5% of adenomas -> colorectal cancer
- time for adenoma to develop into colon cancer is 7-10 yrs
what makes an adenoma a high risk for colorectal cancer
- >10mm
- high grade dysplasia
- villous component
- villous or tubulovillous
What is the most common site of origin of colorectal cancer
- left sided colon (descending)
list the risk factors for colorectal cancer
- personal or family h/o
- adenoma or colon cancer
- FAP/HNPCC
- age > 50
- Inflammatory bowel disease (colitis longer than 8-10 yrs)
- obesity
- diet: high fat/low fiber
- african american
- type II DM
clinical presentation
- often asymptomatic
- abd pain
- change in bowel habits
- hematochezia or occult blood in stool
- weakness and fatigue
- anorexia
- weight loss
- iron deficiency anemia
colorectal cancer
colon cancer can present with what classic sign using barium enema
- “apple core” lesion
What three guidelines are used to screen patients for colorectal cancer
- multisociety task force guidelines
- united states preventative services task force
- american college of gastroenterology
What is the best test to prevent/screen for colorectal cancer
- colonoscopy
- ability to visualize, remove polyps, take biopsies
- requires bowel prep
- requires sedation
- perforation/bleeding risk 1/1000
list the options for CRC screening
- colonoscopy: every 10 years
- barium enema: every 5 years
- flexible sigmoidoscopy: every 5 years
- CT colonography : every 5 years
describe barium enema
- colon coated with barium, air inserted via rectal catheter to distend colon. radiographs taken under fluoroscopy
- requires bowel prep
- no sedation
- positive findings -> colonoscopy
- can miss polyps
describe flexible sigmoidoscopy
- can see distal 1/3 of colon
- no sedation
- enema required
- can remove polyps
- if polyps found -> colonoscopy
describe CT colonography
- produces 2D/3D images of bowel mucosa
- no sedation
- no IV contrast
- requires bowel prep
- positive -> colonoscopy
- can miss flat or smaller polyps
List the CRC detection tests
-
hemoccult testing-guaiac based
- requires 2 specimens on 3 consecutive stools
- FIT: fecal immunochemical test
- fecal DNA
What is preferred CRC detection test
- FIT: fecal immunochemical test
- tests for human globin
- test annually
when should screening for colorectal cancer screening start
- if no risk factors, begin at age 50
what is the multi-society task force recommendation for CRC screening if positive FHx
- 1st degree relative with CRC or adenomatous polyp dx < 60 yo or > or = two 1st degree relatives dx at any age
- colonoscopy every 5 years beginning at age 40 or ten years prior to age of dx
- 1st degree relative with CRC or adenomatous polyp dx > 60 yo or > or = two 2nd degree relatives dx at any age
- begin screening age 40
multi-society task force recommendation for CRC screening if personal history of adenomatous colon polyp or colon cancer
- colonoscopy every 5 yaers
- stop screening when life expectancy < 10 yrs
american college of gastroenterology recommends african americans be screened for CRC at what age
45 yo
What is familial adenomatous polyps
- autosomal dominant
- associated with APC gene mutation
- >100 adenomatous polyps
- 100% will develop CRC (Average age 45)
patients with familial adenomatous polyps also have an increased risk for
- extracolonic cancer
- duodenoal/ampullary
- thyroid
- gastric
- hepatoblastoma
- CNS tumors
screening recommendations for patients who are gene carriers for or have a family hx of familial adenomatous polyps
- sigmoidoscopy or colonoscopy annually starting at age 10-12 until 35-40 if negative
- will also require screening for extracolonic cancer
what is Hereditary non-polyposis colon cancer (lynch syndrome)? what cancers is this patient at increased risk of getting
- autosomal dominant
- risk of developing CRC = 70%
- mean age 40-45
- usually right sided colon ca
- increased risk of multiple cancers
- endometrial (most common)
screening recommendations for Hereditary non-polyposis colon cancer
- annual colonoscopy age 20-25 or 10 years prior to earlier age of onset of affected family member
- also requires annual screening for extracolonic malignancies
