GI lecture 5 Large Bowel Disorders pt 2

one of the MC causes of acute/surgical abdomen

appendicitis

appendicitis

inflammation of the vermiform appendix located at the base of the cecum

initial inflammation of the wall if followed by localized ischemia, perforation, and the development of a contained abscess or generalized peritonitis

MCC of appendiceal obstruction

fecalith

appendicitis clinical features

early symptoms subtle and vary on location of the appendix tip

RLQ pain that begins as periumbilical pain and migrates, anorexia, N/V, fever

McBurney point, Rovsing sign, Psoas sign, Obturator sign

appendicitis diagnosis

labs- mild leukocytosis

CT abdomen- appendiceal diameter >6mm w occluded lumen, wall thickening >2mm, periappendiceal fat stranding, appendiceal wall enhancement, appendicolith

US- appendicitis with appendiceal thickening

appendicitis treatment

appendectomy w/in 24 hrs of presentation + IV pipercillin-tazobactam

nonoperative: IV ceftriaxone + metronidazole or levofloxacin + metronidazole for 1-3 days then oral abx (cefdinir + metro, cipro, amox-clav, or levo + metro) for 7-10 days

appendicitis complication

perforation

leads to localized abscess formation or diffuse peritonitis

typically seen temp >103

needs emergent sx

diverticulosis

rupture of the outer layer of the colon w protrusion of the inner layer through the defect

diverticulosis causes

increased intramural pressure and hard stools

common >50yo, western society, low fiber diet

diverticulosis is MCC of ____ in >/=60yo

hematochezia

diverticulosis diagnosis

sigmoid/colonoscopy or barium enema

what increases risk of bleed in diverticulosis

HTN and NSAID use

diverticulitis

occurs when stool or other particulate matter gets trapped in a diverticulum and abscesses

bacterial proliferation causes inflammation and microperforations of colonic tissue

diverticulitis symptoms

steady deep LLQ pain often w/palpable mass

tenesmus

constipation or diarrhea

fevers, chills, N/V, rectal bleed

diverticulosis/diverticulitis treatment

high fiber diet (mainstay)

metamucil

inpatient diverticulitis treatment

bowel rest

IV hydration

abx- piper-tazo, cipro + metro or cipro + metro

morphine

sx for perf/abscess

percutaneous drainage (abscess >4cm)

diverticulitits surgical treatment

removes diseased segment of bowel, colostomy creation, and ostomy reversal 3 months later

outpatient diverticulitis treatment

clear liquid diet 2-3 days min, amox-clav or cipro + metro for 7-10 days (tho might not be necessary)

bowel obstruction causes

neoplasm, volvulus, incarcerated hernia, stricture, obstipation, intussusception, adhesions

bowel obstructions MC occur in

elderly

bowel obstruction in neonates

imperforate anus or other anatomic abnormalities

can be secondary to meconium ileus

~Hirschsprung disease can resemble colonic obstruction

bowel obstruction presentation

mild, diffuse abdominal pain

N/V

distention

the higher the bowel obstruction

the greater the pain

bowel obstruction PE

may have diminished or absent bowel sounds, abdomen distended and poss. tender

examine inguinal and femoral regions for incarcerated hernias

digital rectal exam to reveal pathology

colonic obstruction is often caused by

left-sided inguinal hernia w sigmoid colon incarcerated in the hernia

hard stools on rectal exam

suggest impaction

soft stools on rectal exam

suggest obstipation (severe/complete constipation)

empty vault on rectal exam

suggest obstruction proximal to the level that the examining finger can reach

positive fecal occult blood on rectal exam

may suggest a more proximal neoplasm

bowel obstruction diagnosis

abdominal xray- distended loops of small bowel and colon

abdominal CT - test of choice

bowel obstruction treatment

NPO, d/c opioids if possible, NGT, IV fluids, avoid prokinetics (can worsen), sx consult

sigmoid volvulus- endoscopic reduction

MCC of bowel obstruction in children

intussusception

generally occurs in infants, often after URI

intussusception

invagination (telescoping) of the intestines

intussusception presentation

vomiting, abdominal pain, currant jelly stools (blood and mucus), lethary, sausage-shaped abdominal mass

intussusception testing

plain films, ultrasound, or contrast enema

intussusception treatment

therapeutic enemas or sx reduction

close-loop obstruction often results from

hernias/herniation, adhesions, or a twist of the mesentery

closed-loop obstruction is occluded at 2 points, causing

blood supply to be cut off = gangrene

closed-loop obstruction treatment

sx emergency - esp if small bowel d/t risk of strangulation and bowel infarction

4th MC new cancer diagnosis

colon cancer

also 2nd leading cause of cancer deaths

colon cancer is more common in people

over 50yo

colon cancer histology

adenocarcinoma (85%), mucinous (12%)

colon cancer risk factors

overweight/obese, not being physically active, processed meats, DM, smoking, alcohol, prior hx of adenomatous polyps, personal hx of UC/Crohn, family hx of inherited colorectal cancer symptoms

inherited colorectal cancer syndromes

familial adenomatous polyposis (FAP)

hereditary nonpolposis colorectal cancer (HNPCC)

Lynch syndrome

hereditary non-polyposis colorectal cancer

autosomal dominant

should suspect w/diagnosis

FAP

gene mutation causing hundreds-thousands of colon polyps beginning at age 10-12

cx usually develops by 20yo

3 subtypes of FAP

attenuated FAP-

Peutz-Jeghers syndrome (PJS)

rare, caused by genetic mutation

pts have hamartomas in digestive tract that places them at v high risk for colorectal, breast, ovarian, and pancreatic cx

diagnosed at younger age

PJS patients typically have

freckles around the mouth

sometimes on hands/feet

USPSTF colon cancer screening

everyone age 45-75

American Cancer Society colon cancer screening

everyone age 45-75, may perform up to 85yo in select populations

indicates earlier/more frequent colon cancer screening

family hx of inherited syndromes (FAP, HNPCC)

strong family hx of CRC or polyps

personal hx of CRC or polyps

personal hx of chronic IBD

screening if 1st degree relative has colon cancer hx

start at 40yo or 10 years before relative was diagnosed (whichever is earliest)

screen w colonoscopy every 5 years or more often dep. on results

FIT screening annually

colon cancer screening methods

colonoscopy- every 10 yrs

FOBT - every year

FIT- every 3 years

flexible sigmoidoscopy- every 5-10 years, usually w FOBT every 1-3 years

double contrast barium- every 5 years

if FOBT or FIT are positive

colonoscopy is needed

polyps

grossly visible mass that protrudes from the mucosal surface into the lumen of the intestine

source of rectal bleeding or partial bowel obstruction

can be non-neoplastic or neoplastic

sessile polyp

flat

pedunculated polyp

thin stalk that supports an irregular top

adenomatous polyps increase risk for

development of adenomas and colorectal adenocarcinoma

from time of polyp formation to cancer is approx

10 years

non-neoplastic polyps

hyperplastic, juvenile, inflammatory, submucosal lesions

colon cancer mets are commonly on

liver, lungs, peritoneum

colon cancer s&s

rectal bleeding, hematochezia/melena, abdominal pain, change in bowel habits, ascites/hepatomegaly if liver is involved, weight loss

consider colon cancer in adults >50yo w/ new

iron-deficiency anemia

colon cancer diagnosis

-colonoscopy w biopsy (gold standard)

-CT scan- generalized abdominal symptoms

-flex sigmoidoscopy- most effective for palpable masses felt in rectum

-CT colonography- often used when there is an incomplete colonoscopy

colon cancer tumor markers

carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9)

should not be used as screening tools

CEA levels >5ng/mL pre-op have

worse prognosis

CEA levels maintained or increased after sx indicates

aggressive disease

only curative modality for localized colon cancer

surgical resection (stage I-III)

can poss. provide curative option in stage IV disease

standard treatment for stage III colon cancer

sx + chemotherapy

role of radiation in colon cancer treatment

limited to palliative therapy for metastatic sites (bone, brain mets)

standard management for patients w metastatic colorectal cancer

chemotherapy, biologic agents w selection guided by genetic analysis of tumor

survival of colon cancer is inversely related to

stage (localized > distant)