small intestine and Colon Disorders Flashcards
how common are colon polyps?
very common- either benign or malignant
are polyps heritable?
yes! familiar adenomatous polyposis, hamartomatous polyposis (Peutz-Jeghers syndrome, familial juvenile polyposis, PTEN multiple hamartoma syndrome)
what is the link btw colon polyps and colon cancer?
- removal of polyps reduces the risk of colon cancer
- if one of the inherited polyp syndromes: almost 100% risk of developing colon cancer, up to 5% of colon ca comes from one of these syndromes
what are the sx of colon polyps?
- generally asx
- may see constipation, flatulence, and rectal bleeding
what are secondary complications of colon polyps?
iron deficient anemia
what are dx studies that can be done if suspicious of polyps?
- stool guiac
- barium enema, flexible sigmoidoscopy, and colonoscopy
- histological evaluation
what does histological evaluation help you determine if pt has polyps?
dysplasia: hyperplastic polyps have the lowest risk of dysplasia
tubular polyps are at an increased risk
villous polyps carry the highest risk of malignancy
what are the 3 classifications of polyps?
hyperplastic, tubular, and villous
how are polyps tx?
depends on the size and histology
what should tx be if large and dysplastic polyps?
removed w/ subsequent follow ups
what about a single distal hyperplastic polyp?
same recommendation of every 10 years as someone w/o polyps
what about multiple hyperplastic polyps, hyperplastic polyps at sites rather than distal, or tubular polyps?
require a 5 year follow up
what about villous polyps?
require follow up colonoscopy at 3 years
what if a pt has family members wi/ familial polyposis syndrome?
evaluated every 1-2 years beginning at age 10-12 yo
-elective colectomy may be an option for high risk individuals
what age group is mostly likely to be diagnosed with colon cancer?
pts over 50
what are risk factors for colon cancer?
IBD (more UC than Crohn’s)
family history of colon cancer or polyps
personal hx of polyps
hereditary polyposis syndromes:Familial polyposis, Gardner’s Syndrome, Turcot’s Syndrome (bascially 100% risk of developing this dz)
what is hereditary nonpolyposis colorectal cancer?
aka lynch syndrome: leads to an extremely high risk of colon cancer: autosomal dominant that accounts for 3% of colon cancer
what lifestyle features are related to colon cancer
Low fiber diet High fat diet Alcohol (beer) intake Obesity Prolonged/high consumption of red meat or processed meat
what is the prognosis for colon cancer?
good, in early dz
what is Duke A or stage 1?
only mucosa involvement
5 yr survival rate is 90%
what is duke B or stage II colon cancer?
penetration through the wall or involvment of regional lymph nodes
5 year: 70-80%
what is Duke C or Stage III?
metastasis: lymph node postitive
5 year: 5%
what is Duke D or Stage 4?
distant metastases
5 year: 5%
what are clinical features of colon cancer?
-slow growing, and sx often appear late int he dz:
abdominal pain, change in bowel habits, occult bleeding (stool size and shape, blood), intestinal obstruction
*pencil thin stools
what are features of right sided colon lesions?
chronic blood loss and iron deficiency anemia
obstruction is uncommon
what are left sided colon lesions features?
circumferential, causing change in bowel habits and obstructive symptoms
what are secondary clincal features of colon cancer?
fatigue and weakness secondary to anemia
are the diagnostic studies for colon cancer
- FOBT
- CEA
- LFTs
- CBC (microcytic anemia)
- colonoscopy
what is the most common site of colon cancer metastses?
the liver, so check LFTs
what is CEA?
(Carcinoembryonic Antigen): Colon cancer tumor marker. Can be high in other circumstances: tobacco use, IBD, alcoholic liver disease. Therefore, not used for screening.
what is used to checkfor metastses?
CT of CXR
what is the colonoscopy recommendations?
Beginning at age 50 and repeated every 10 years in average-risk patients
Screening in African Americans should begin at age 45
If personal history of colon polyps, every 5 years
If a first-degree family member has had CRC, screening should start at age 50, or 10 years before age of diagnosis, which ever is younger; and this should be repeated every 5 years.
what is the treatment for colon cancer?
surgical resection that is accompanies by chemo in stages III or higher
celiac disease?
inflammation of small bowel secondary ot he ingestion of gluten-containing foods such as wheat, rye, anc barley leading to malabsorption
clinical features of celiac dz?
- highly variable
- D, steatorrhea, flatulence, weight loss, wkns, abdominal distenstion
what can older pts with celiac dz present with?
Fe deficiency, coagulopathy, hyopcalcemia
what dx studies can be done for celiac dz?
IgA antiendomysial (EMA) and atnitissue transglutaminase (anti tTG) are serologic screening test
what needs to be done to confimr dx of celiac dz?
small bowel biopsy
how is celiac dz treated?
involes gluten free diet, may also need lactose free diet
- vitamin supplementation: iron, vit B 12, folic acid, ca, vit d
- prednisone in refractory cases
diverticular dz?
diverticulosis= large outpouching of the mucosa in the colon diverticulitis= inflammation of the diverticula caused by obstruction
how can diverticulitis be prevented?
high-fiber diet and avoidance of obstructing or constipated foods
what is the presentation of diverticulitis?
sudden-onset abdomnial pain, usually in LLQ or suprpubic region +/- fever
+altered bowel movement like N, V
how may diverticular bleeding present?
sudden-onset, large volume hematochezia that can resolve spontaneoulsy
dx of diverticulitis?
occult stool: WBC
plain film xray to rule out free air
avoid barium enema
tx of diverticulites
broad spectum abx: cipro, metronidazole, bactrim , augment, moxifloxacin
how does chronic ischemic bowel dz present?
abdominal angina, w/ pain occuring 10-30 mins after eating, relieved by squatting or lying down
PE normal
what part of the bowel is intestinal infarct more common?
small bowel- can lead to shock!
what can cause acute mesenteric ishcmeia?
arterial embolus, arterial thrombosis,, venous thrombosis
how is ischemic bowel dz diagnosis?
plain film radiograpy and CT to r/o toher causes
duplex US that may be confriemd by angiography
