Small Intestine And Colon - Dr. Dobson Flashcards
most common site of GI neoplasia in Western populations
colon
when does the intestines rapidly grow and what happens
week 4 and 5
= causing the abd cavity to be overfull and intestines herniate out the umbilical cord
week 4
NCC enter foregut
week 7
NCC reach the hindgut
week 9
cloaca becomes patent and villus formation begins
week 11
mature SM layers along GI tract
procedure for the capsule endoscopy
- fasting prior to swallowing capsule
- Capsule goes through GI
- wireless recorder around waist receives signals from capsule by sensors on pt body
capsule advantages
no sedation
3D coloc images
80% of mechanical obstructions in GI are from what 4 things
- Hernia
- Adhesions
- Vovlulus
- Intussusception
common SX of SIO
constipation, ABD distention and Pain, Vomiting
Functional Bowel obstruction
paralysis of ileus due to peristalsis disturbance from NO mechanical obstruction = usually from postoperative ileus = hypokalemia = hypothyroidism = anti-cholinergics
hernias can cause what
trapped vein causing blood to pool and get stuck leading to infarction
what can cause adhesions
surgery
trauma
intraabdominal infection
endrometriosis
most common cause of obstruction World wide and in US and in children under 2yo
World : Hernias
US : adhesion
children under 2yo : intussusception
vovulus happens most frequently where
Sigmoid colon**
cecum/ SI / stomach, rarely TC
patient with obstruction what do you do first
restore electrolyte imbalance
then do endoscopic decompression
who is in risk of intussusception
viral infection, rotavirus vaccination , tumor in GI, 1% Cystic Fibrosis patients
angiodysplasia
small fragile, swollen and easily rupturing small mucosal and submucosal vessels, usually in colon and right side of colon (AC) or cecum
= after 6th decade in life
SMA supplies what
illeum, AC, 2/3 TC
IMA supplies
1/3 TC, DC, Sigmoid Colon, Rectum
Celiac supplies
left stomach, liver, spleen
what vessels are big arteries that would cause ischemia in a large area of the instestines
- Ileocolic A
- Right Colic A
- Middle Colic
- Marginal A ** esp**
- Left Colic
- Signmoid A
Mesenteric Venous thrombosis happens how
- Hypercoagulable state
- Tumors
- Trauma
- Cirrhosis
Vascular Obstruction caused by
- severe atherosclerosis
- AAA
- Cardiac mural thrombi
- Vasculitis
chronic hypoperfusion causes by
- cardiac failure
- shock
- dehydration
- Drugs (vasocontrictors)
2 stages of ischemia
phase 1 : vascualr compromise
phase 2 : reperfusion injury from restoring Blood supply = leakage of gut bacteria into circulation, free radicals, N infiltration, inflammation
acute ischemia SX and who
usually over 70yo slightly more in F
- LLQ pain, need to poop, bloody D
Surgery should be done when in acute ischemia
if evidence of infarction = low bowel sounds, guarding, rebound tenderness
chronic ischemia SX
- ABD pain after 30min of eating, worsens over hour
- pain goes away after 1-3 hours
- if not treated can become severe acute ischemia
transmural artery occlusion mortality rate
10% first 30 days
which artery if occluded will cause worst outcome
SMA
angiodysplasia is how common in elderly
20% of intestinal bleeding cases in elderly
Abetalipoproteinemia
inability to absorb fat
D, malabsorption
Microvillous inclusion disease
abnormal microvilli inclusions giving D and malabsorption
environmental enteropathy
chronic fecal oral contamination giving inflammation and D and malabsorption
autoimmune enteropathy
autoimmune in children causing a lot of D they need to be on IV fluids
hallmark of malabsorption
steatorrhea = excessive fecal fat, bulky, grease, yellow, claycolored
3 most common reasons for malabsorption in US and one not as common only
- Pancreatic insufficiency
- Celiac Disease
- Crohn’s Disease
- Graft vs Host hematopoietic stem cell transplantation
dysentery
painful, bloody, small volume D
Secretory D
isotonic stool, during fasting times
= low area to absorb, from bacteria or medications
= continual water pulled out into GI
Osmotic D
= lactase deficiency, excessive osmotic forces exerted by unabsorbed luminal solutes
= more concentrated D fluid
Malabsoptive D
X nutrient absorption = steatorrhea
fasting helps
Exudative D
D from inflammation disease
= purulent, bloody D continuing during fasting
Cystic Fibrosis and GI
- pancreatic abnormalities (85%-90% patients)
= mucus clogs the pancreatic exocrine ducts
= X fat absorption with no pancreatic excretion
= vitamine def, squamout metaplasia of pancreatic duct lining - mucous plugs in SI = SIO = meconium ileus
foods that cause celiac disease to flare up
wheat, rye, barley
autoimmune to own Lymphocytes with the gluten food products
what can put someone at risk of celiac disease
infection, tissue damage
how is gluten recognized and activating the immune system in CD
Gliadin (monomer of gluten) activates
- Innate IS : CD8+ (by IL15)
- Adaptive IS : CD4+ and Bcells
HLA involved in CD
DQ2 and DQ8 on the DC that show the gliadin to T cells
how to DX CD
- Villous atrophy
- tTG antibody serologic test (IgA antibody to tTG) **
- Gliadin AB are not very good to dx
SX of CD in adults
higher in F (30yo - 60yo)
- chronic D
- bloating
- chronic fatigue
- malabsorption
- dermatitis herpetiformis
SX of CD in children
F= M (6mo = 24mo)
- irritability
- abd distention
- chronic D, abd pain, N /V
- weight loss
- arthritis *, joint pain, ulcers, stomatits(inflamed mouth), anemia, delayed puberty
Dermatitis herpetiformis
pruritic, small vesicles, microabscess, subepidermal blister, IgA granular deposits
= IgA anti-gluten AB react with BM proteins (tTG)
Enviornmental Enteric Dysfunciton ( Enviromental Enteropathy, tropical enteropathy, tropical sprue)
- where
- how
- what happens
- subsaharan africa, Zambia, (northern australia)
- poor hygiene and sanitation
- malabsorption, D, lower growth
Autoimmune eneropathy
- what is it
- who
- what happens
- gene
- X- linked disorder
- children
- severe persistant D and autoimmune disease
- FOXP3 gene loss in the IPEX kind
Autoimmune eneropathy
- MOA
- Histology
- TX
- autoABs to enterocytes and goblet cells (sometimes parietal and islet cells)
- N in the intestinal mucosa (NOT seen in celiac D)**
- immunosuppressive drugs = cyclosporine, hematopoietic stem cell transplantation
IPEX is what
familial type of Autoimmune eneropathy
= immune dysregulation, polyendocrinopathy, enteropathy, X-linked
Lactase Deficiency
- other name
- MOA
- Disaccharidase
2. Lactose cant –> Glucose and Galactose = osmotic D
Congenital Lactase Deficiency
what and SX
mutation in lactase enzyme
AR
= explosive D, abd distention when milk ingestion
Acquired lactose deficiency
what is it and who and risks
downregulation of lactase enzyme gene expression (esp native americans, AA, Chinease)
= viral infections, bacterial infections, can resolve over time
Microvillous Inclusion Disease
- MOA
- gene
- histology
rare AR
= Vesicular transport limited from X brush boarder assemble
= MYO5B (encoding motor protein)
= accumulation of abnormal apical vesicles of microvilli and membrane components
Microvillous Inclusion Disease
- who
- DX
- TX
- European, Middle eastern, Navajo Native Americans
- immunostaning for brush boarder protein villin (CD10 immunohistochemistry)**
- parenteral nutrition and SI transplantation
Abetalipoproteinemia
- what MOA
- who
- SX
- AR, X assemble TAG right lipoproteins
- infants
- steatorrhea, failure to thrive, D
Abetalipoproteinemia
- Histology
- effects this disease has
- plasma has no lipoproteins with apolipoprotein B, defect in plasma membranes, Acanthocytes in blood smear
- vitamine deficiency
Abetalipoproteinemia gene and how it is supposed to work
MTG gene mutations
= transferes TAGs into the apolipoprotien B in the ER,
= matation causes TAGs to accumulate in ICF
Infectious enterocolitis broad SX and deaths per day in world
D, ABD pain, urgency, perianal discomfort, incontinence, hemorrhage
= 2000 deaths / day
= 10% deaths by age 5yo
fecal leukocyte count
few
moderate
many
few : < or = 2 oil immersion microscopic field
Moderate : 3 OIF - 9 OIF
Many : 10 or more OIF
Many fecal leukocytes means
invasive pathogen like shigella or salmonella
few fecal leukocytes means
IF high erythrocytes = amebiasis
PCR for Infectious enterocolitis
test for tcdC (toxin genes)
selective serology for Infectious enterocolitis
Giardia Ag
Vibrio cholerae
- bacteria type
- where
- MOA
- comma-shaped, gram -
- Ganges Valley India, Bangladesh
- over activated CFTR = pumping Cl- out and watery D
Campylobacter Enterocolitis
- other name
- from what
- C. jejuni = travelers D
2. food poisoning chicken, unpasteurizes milk, contaminated water
Campylobacter Enterocolitis
- SX
- can cause what 3 things**
- Bloody or Watery D, bloody only if invasive bacteria strain going throught tight junctions
- Reactive Arthritits : IF HLA-B27**, Guillain-Barre, Erythema nodosum
Campylobacter Enterocolitis and enteric fever
the bacteria proliferates in the lamina propria and causes nonspecific fever, abd pain
Guillain- Barre syndrome
SX and TX
- acute inflammatory demyelination of neurons in hands and feet usually traveling up the leg
- low or absent DTR
- Resp muscle weakness need to be on ventilator (when traveling up that far)
TX : plasma exchange + IV Ig
erythema nodosum
inflammation in fatty layer of skin, off and on inflammed and reddish painful lumps legs front, then become bruise like and flatten out
Shigellosis
- bacteria type
- close related to what
- most common cause of what in the world
- gram -, unencapsulated, nonmotile, facultative anaerobes
- E. coli
- Bloody D
Shigellosis
- who in US
- deaths in world
- daycare children, migrant workers, traveling to low resource countries, nursing homes
- 75% death rate in children younger then 5yo
Shigellosis
- attacks where in the GI
- histology
- can look like and be confused with
- left colon, ileum
- M in dome epithelium over Peyer patche, hemorrhaging + ulcerated mucosa, pseudomembranes
- M cells and aphthous ulcers similar to what is seen in Crohns Disease
Shigellosis
- time line of infection
- children vs adults
- can mimic what disease
- DX
- incubation 1 week, 7-10day D, fever, abd pain (enteric fever) = initially watery and 50% becomes bloody 1 for up to month long
- more severe only shorter duration in children
- waxing and waning D = looks like new onset ulcerative colitis in adults
- stool culture
Shigellosis contraindication for TX and indicated TX
DONT give anit-diarrheal medication, prolongs infectiong and delay clearence
- give antibiotics