GI - Large and small intestine Flashcards
what is intestinal failure
when the gut can no longer supply hydration and nutritional needs of body - failure of ability to absorb food via intestines
what is type 1 intestinal failure associated with
short term - post op, chemo
what qualifies as acute intestinal failure
lasting 2 weeks
type 1 and type 2
what is type 2 intestinal failure associated with
sepsis abdo fistula /Crohns metabolic comp ischaemia prolonged surgery comps
what is the treatment of acute intestinal failure
parenteral nutrition if unable to tolerate food/fluid - 7 days post op but allow as much enteral feeding as possible
PPI
Octreotide (reduced bowel movements)
alpha-hydroxycholecalciferol (preserves Mg)
what is type 3 intestinal failure
chronic - SBS
what length of bowel qualifies as SBS
< 200cm functioning small bowel
what is the treatment of chronic SBS
home parenteral nutrition
PPI
if venous access lost or liver disease - transplant
what are some complications of parenteral nutrition
pneumothorax arterial puncture misplacement endocarditis (venous lines) hepatitis (venous lines)
where is access for parenteral nutrition gained
via subclavian/internal jugular vein - US guided
what nutrient deficiencies is referring syndrome associated with
hypokalaemia
hypophosphataemia
hypomagnesaemia
what is referring syndrome
imbalances in fluid and electrolytes leading to cell/organ damage
what can refeeding syndrome result in
arrhythmia
CF
death
what are some s/s of small bowel obstruction
intermittent episodes of colicky pain absolute constipation - no flatus/burping abdominal distension faeculent vomiting high pitched/tinkling bowel sounds (like water against a boat) obstruction may be palpable lack of abdo tenderness visible peristalsis
if copious volumes of bile stained fluid was vomited where would you suspect the obstruction was
upper small bowel
if semi-digested food eaten half a day ago was vomited where would you suspect the obstruction was
gastric outlet
how does bowel obstruction look on an investigation
dilation of bowel proximal to the obstruction and collapsed bowel distal
what are the investigations for bowel obstruction
supine AXR - looks for distension
CT - confirm and look for cause
what is the treatment of bowel obstruction
NBM cannula - take blood and IV fluids NG tube to decompress stomach (drip and suck) anti embolism measures
what are some causes of bowel obstruction
congenital tumour hernia - abode wall/internal volvulus post op comp strictures - Crohn's, Diverticular (usually incomplete) intususceptioin GS ileus adhesions
what is strangulation of the bowel
twisting of bowel in loops around itself cutting off blood supply
what does strangulation of the bowel lead to
progresses to infarction and perforation due to arterial inflow compromise
what are some s/s of strangulation
constant pain "pain over hernia" - can occur in external hernia or volvulus sepsis/shock MSO failure death
what is the treatment of strangulation
urgent surgery
how is perforation of bowel diagnosed
erect CXR - free subphrenic gas
CT may help find source
what is paralytic ileus
Obstruction of the intestine due to paralysis of the intestinal muscles
what are the s/s of paralytic ileus
similar to obstruction but tinkling bowel sounds and pain less common
what is the treatment of paralytic ileus
drip and suck while awaiting restoration of peristalsis
what is pseudo-obstruction (ogilvie’s syndrome)
acute dilation of colon in absence of colonic obstruction in acutely unwell patients
what bowel obstruction is associated with hip replacement CABG spinal anaesthesia pneumonia frail/eldering
pseudo-obstruction
ogilvie’s syndrome
how is pseudo-obstruction diagnosed
AXR +/- CT
confirms gaseous distension proximal to distal rectum
what may be required in pseudo-obstruction
colon may require colonscopic decompression
when is surgery done early in SBO
strangulation
ischaemia
perforation
to prevent dead guts
what does acute mesenteric ischaemia usually affect
small bowel
why is the large bowel less commonly affected by acute mesenteric ischaemia
marginal artery of drummond
what are some s/s of acute mesenteric ischaemia
elderly acute severe abdominal pain poorly localised cramping rapid hypovolaemia --> shock reduced bowel sounds
true/false
acute mesenteric ischaemia is associated with AF
true
what are some causes of acute mesenteric ischaemia
volvulus
SMA thrombosis/embolism
mesenteric vein thrombus - affects smaller lengths of bowel
low flow states - poor CO, post cardiac surgery, renal failure
what are some complications of acute mesenteric ischaemia
gangrene
translocated bacteria across dying gut wall
septic peritonitis
MODS
what is the treatment of sepsis caused by acute mesenteric ischaemia
fluids
gentamicin + metronidazole + heparin
what is the treatment of acute mesenteric ischaemia
surgery to remove dead bowel
revascularisation - arteriography + thrombolysis
what are some tests for acute mesenteric ischaemia
increased Hb increased WCC increased plasma amylase AXR - gasless abdomen CT/MRI angiography
what gut layer is most sensitive to ischaemia
mucosa - most metabolically active
what is chronic mesenteric ischaemia also known as
intestinal angina
what are some s/s of chronic mesenteric ischaemia
severe, colicky post prandial abdominal pain weight loss upper abdominal bruit \+/- PR bleeding malabsorption N+V
often Hx vascular disease
how is chronic mesenteric ischaemia diagnosed
CT/MR angiography
Doppler US
what is the treatment of chronic mesenteric ischaemia
surgery
percutaneous transluminal angioplasty
stent (palliative)
what are some complications of chronic mesenteric ischaemia
scarring and fibrosis –> stricture
gangrene
perforation
what is ischaemic colitis
chronic colonic ischaemia
where does ischaemic colitis most commonly affect
sigmoid colon
who does ischaemic colitis affect
elderly
those at risk of atherosclerosis
what are some s/s of ischaemic colitis
lower left sided abdominal pain
+/- bloody diarrhoea
what does ischaemic colitis look like on a barium enema
THUMB PRINTING OF SUBMUCOSAL SWELLING AT SPLENIC FLEXURE
what are some investigations for ischaemic colitis
colonoscopy + biopsy - gold standard
CT
barium enema
what is the histological appearance of ischaemic colitis
withering of crypts
pink smudgy lamina propria
fewer chronic inflammatory cells
how is ischaemic colitis caused and what can is progress to
low flow in IMA
mild ischaemia
gangrenous colitis
peritonitis/hypovolaemia shock
what is the treatment for ischaemic colitis
fluids and antibiotics
resection of affected bowel (gangrenous colitis) + stoma
true/false
strictures are common in ischaemic colitis
true
what is volvulus and what does it cause
twisting of bowel along mesentery - cause of acute mesenteric ischaemia
obstruction and disruption of blood flow –> infarction –> gangrene
where does volvulus affect elderly
sigmoid
where does volvulus affect young adults
caecum
how is volvulus diagnosed
AXR
what is the treatment of volvulus
flatus tube + sigmoidoscope (removes flatus and fixes volvulus)
surgical resection
what is intussusception
part of intestine invaginate into another section of intestine
often causing obstruction
what is the most common cause of intussusception in children (emergency)
lymphoid hyperplasia due to rotavirus in terminal ileum
leads to intussusception in caecum (ileocaecal junction)
what are the s/s of intussusception
current jelly stool/red currant stool
bullseye appearance on US
what is the most common cause of intussusception in adults
tumour
what is a diverticulum
mucosal herniation through muscle coat usually at sites of arterial perforation - out pouching of gut wall
what is a true diverticulum
involves all layers of the gut wall
what is a false diverticulum
just mucosa and serosa
where are diverticula most commonly found
sigmoid colon
how is diverticulosis diagnosed
incidental finding on endoscopy
what is diverticulitis
inflammation of diverticulum e.g. from blockage - food, seeds
what is the cause of diverticulum
low fibre diet - high intraluminal pressures and stool more liquid so higher pressure contractions needed
what classification is used for acute diverticulitis
hichney
what are some s/s of diverticular disease
LIF pain/tenderness relieved by defecation nausea flatulence if diverticulitis - pyrexia, increased WCC CRP and ESR
what are some investigations for diverticular disease
sigmoidoscopy
Ba enema
CT - first line for diverticulitis
what are some complications of diverticular disease
fistula stricture pericolic abscess haemorrhage - rectal bleeding perforation - shock sepsis
what is the most common fistula associated with diverticular disease
colovesical - bladder
what is the treatment of diverticular disease
fluids/rest/oral ABs
if complicated:
Percutaneous drainage
Hartmann’s procedure
what is Hartmann’s procedure
remove sigmoid colon and attach colostomy bag to descending colon
is meckel diverticulum true or false
true
what is meckel diverticulum
distal ileum contains embryonic remnants of gastric and pancreatic tissue due to the incomplete regression of the vitello-intestinal duct - gastric acid secretion
where does meckel diverticulum occur
60cm from ileocaecal valve
what are some s/s meckel diverticulum
pain
rectal/faecal bleeding
can mimic appendicitis
when does meckel diverticulum usually present
1st 2 years of life
how is meckel diverticulum diagnosed
Technicium Tc 99M scan
what kind of inflammation if crohn’s
transmural
where does crohn’s affect
any part of GI tract from mouth to anus
where is Crohn’s most commonly seen
terminal ileum
proximal colon
how do strictures form in Crohn’s
omentum (fat) wrapping around bowel
is Crohn’s inflammation continuous
no - skip lesions
what is the appearance of Crohn’s
cobblestone mucosa
deep fissuring ulcers
what happens to the colon walls in Crohn’s
thickened
are granulomas seen in Crohn’s
yes
non-caseating granulomas
what are some causes of Crohn’s
smoking
infection
NSAIDs
what gene is mutated in Crohn’s
NOD2 (IBD-1) - on C16 - encodes protein involved in bacterial recognition
CARD15
what immune cells mediate Crohn’s
TH1
- ILN, TNF, macrophages
who does Crohn’s affect
20 - 40 yos
does Crohn’s affect men or women more
men
what is the treatment of Crohn’s
Steroids - short course, high dose
Immunosuppressants - maintenance
Anti-TNF
name 3 steroids used in Crohn’s
prednisolone (oral)
budesonide (oral)
hydrocortisone
name 2 immunosuppressant used in Crohn’s
azathioprine
methotrexate
name 2 anti-TNF therapies used in Crohn’s
antibodies to TNF
infliximab - IV - chimeric
adalimumab - SC - humanised
what are some complications of Crohn’s
bowel obstruction abscess Fistula Malabsorption Stricture Perforation SBS osteomalacia malnutrition amyloidosis
are extra GI symptoms common or rare in Crohn’s
rare
what extra GI symptoms might be seen in Crohn’s
clubbing
skin/joint/eye problems
what is the risk of developing CRC from Crohn’s
moderate
true/false
there may be a RIF mass in Crohn’s
true
how is Crohn’s diagnosed
endoscopy + barium imaging of SB
CT, MRI, Colonoscopy
Technetium labelled white cell scan
what would the bloods of Crohn’s look like
raised CRP, albumin, platelets, B12, ferritin
is surgery for Crohn’s curative
no
what are the s/s Crohn’s in the SB
periumbilical abdominal cramps
diarrhoea
weight loss
what are the s/s Crohn’s in the colon
lower abdominal cramps
diarrhoea + blood
what are the s/s Crohn’s in the mouth
ulcers
angular chelitis
swollen lips
what are the s/s Crohn’s in the anus
peri-anal disease - recurrent abscess formation leading to fistula with persistent leakage and damaged spinchters
pain
what is a technetium labelled white cell scan
a means of detecting infection in bone joints and soft tissue as well as inflammation due to other causes such as IBD
what does elevated ESR indicate
presence of inflammation
what is ESR
rate at which red blood cells settle out in a tube of unclotted blood mm/hr
what is intermediate colitis
overlap of Crohn’s and UC
what is Rigler’s sign
air on both luminal and peritoneal side of bowel wall - perforated ulcer
what are the side effects of corticosteroids
avascular necrosis osteoporosis/growth failure acne thinning of skin weight gain/increased appetite diabetes hypertension cataracts
why does budesonide not have many systemic side effects
undergoes 1st pass metabolism in liver
what are some side effects of azathioprine
hepatitis
pancreatitis
skin cancer
leukopenia (FBR)
what drug should be avoided with azathioprine
allopurinol
what is the onset of azathioprine like
slow
what do the letters in SNAP stand for
Sepsis
Nutrition
Anatomy
Plan
what is measured before azathioprine is prescribed and why
TMPT levels - people with TMPT enzyme problems are more susceptible to infections as azathioprine lowers the WCC - TMPT is responsible for converting some of 6-MP into 6-MMP - if not working/not present higher levels of ^-TGN (active form of azathioprine) - more likely to reduce WCC
how does Anti-TNF work
promotes apoptosis of activated T-lymphocytes
what type of inflammation is seen in UC
mucosal inflammation
is UC inflammation continous
yes
where is UC seen
rectum and extends proximally to colon
who does UC affect
non-smokers
20-30 yos and elderly
does UC affect men or women more
men
what immune cells mediate UC
Th1 and Th2
how is severe US classified
> 6 bloody stools in 24 hours \+1 of Fever Anaemia Tachycardia Elevated ESR
Truelove + Witt Criteria
what kind of things aggravate UC
NSAIDs
infection
ABs
is the risk of CRC greater in Crohn’s or UC
UC
are there granulomas in UC
no
what are some characteristics of UC
Cryptitis / Crypt abscesses loss of haustra thin walled granular mucosa absence of goblet cells superficial ulceration
what is the disease extent of proctitis
rectum - no more proximal than sigmoid colon
what is the disease extent of left sided colitis
rectum and left colon - no more proximal than splenic flexure
what is the disease extent of pancolitis
rectum and entire colon
what is seen in the bloods of UC
CRP
Albumin
what is seen in an AXR of UC
stool absent from inflamed colon
toxic megacolon
how is UC diagnosed
Endoscopy + biopsy
what is seen on endoscopy of UC
loss of vessel pattern
contact bleeding
pseudopolyps
what is the treatment of UC
5ASA (mesalazine)
steroids
immunosuppressants
Anti-TNF
is surgery of UC curative
yes
what are 2 options of surgery in UC
permanent ileostomy
restorative proctocoloectomy + pouch
what are some s/s UC
diarrhoea + bleeding increased bowel frequency urgency tenesmus incontinence night rising lower abdominal pain (LIF)
what are some complications of UC
CRC cholangiocarcinoma anaemia shock (bleeding) toxic megacolon
how does UC lead to CRC
chronic inflammation –> dysplasia –> carcinoma
is UC or Crohn’s associated with PSC
UC
what is the surgical treatment of duodenal or pyloric stenosis
gastrojejunostomy
what is amyloidosis
deposition of abnormally folded protein
are extra-GI symptoms common in UC
yes
what are some extra-GI symptoms of UC
erythema nodosom joint/eye/skin problems ankylosing spondylitis steatosis gall stones episcleritis iritis sacriolitis malnutrition clubbing pyoderma
true/false
5ASA reduces risk of CRC
true
what are some side effects of 5ASA
diarrhoea
idiosyncratic nephritis
how can 5ASA be administered
topical
enema
suppositorie (oral) - drug coated to delay release of drug until in bowel
why are topical 5ASAs inserted up rectum
- to avoid systemic side effects - 1st pass metabolism in liver meaning very little of drug exits into systemic circulation
what has better mucosal adherence
suppositorie or enema
suppositorie
what is better at reaching sigmoid colon
suppositorie or enema
enema
what is the Rome III criteria for IBS
recurrent abdominal pain for atleast 3 days / month for 3 months \+2 of - improvement on defecation - change in stool frequency - change in stool form
what are some triggers of IBS
bread/fibre infection drugs e.g. opiates menstruation physiological factors
what are some s/s of IBS
abdo pain change in stool frequency change in stool form improvement of pain on defecation urgency tenesmus bloating/distension mucus PR worsened by stress exaggerated gastro-colic reflex
what is IBS associated with
visceral hypersensitivity
fibromyalgia, chronic fatigue syndrome/depression, TMS dysfunction, chronic pelvic pain
is IBS worse in men or women
women - oestrogen driven disease
when should a person with suspected IBS get an endoscopy
> 55
Fhmx CRC
red flags e.g. waking up with need to dedicate, recent onset, rectal bleeding, weight loss, anaemia
what are some investigations done in IBS
FBC (anaemia)
ESR/plasma viscosity/CRP/TTG
what is the treatment of IBS
reduce fibre/dairy/gluten stop opiates e.g. codeine antidiarrhoeals - loperamide antispasmodics - buscopan, mebeverine, hyoscine antidepressants - amitryphylline
what is a SE of amitryphylline
drowsiness - take at night, resets nerves in bowel
what is the treatment for constipation in IBS
movicol
what genes trigger coeliac disease
HLA-DQ2 and HLA-DQ8
what antibodies are present in coeliac disease
antiendomesial anti-gliadin Abs
IgA anti-tissue transglutaminase Abs
what type of hypersensitivity reaction is coeliac disease
type IV
what immune cells are responsible for coeliac disease
Helper T cell mediated - mediate tissue damage following presentation by antigen presenting cells via MHC class II
what happens in coeliac disease
immune reaction (T cells) to gliadin in wheat fluid/gluten in small intestine (proximal) gluten specific T cells produce IFN-Y which triggers intraepithelial lymphocytes and kills epithelial cells damages enterocytes and reduces absorptive capacity
what is seen in the histology of coeliac disease
flat duodenal mucosa (villous atrophy)
what does loss of villous structure in coeliac disease cause
loss of absorptive SA
reduction in absorption
- malabsorption
what nutrients are malabsorbed in coeliac disease
CHOs fats AAs water electrolytes vitamins Fe, B12, folate
what are some s/s coeliac disease
abdominal distension diarrhoea failure to thrive (children) bloating dermatitis herpetiformis flatulence anaemia steatorrhoea
what childhood disorder is coeliac disease associated with
childhood diabetes
- think of MH
what is the treatment of coeliac disease
gluten free diet - damage is reversible
how is coeliac disease diagnosed
duodenal biopsy after a positive tTGA test (patient still eating gluten)
what are some complications of coeliac disease
T cell lymphoma
Small bowel carcinoma
gallstones
what causes lactose intolerance
decreased function of lactase enzyme
where is lactase enzyme found
brush border of enterocytes
what does lactase normally break down
lactose into glucose and galactose
what are some s/s of lactose intolerance
flatulence
distension
diarrhoea
following lactose consumption
what causes the s/s of lactose intolerance
presence of lactose in colon –> colonic flora produce CO2, H2 and methane
what is a test for lactose intolerance
H2 breath test
what inheritance in congenital lactose intolerance
rare AR disorder
why can small bowel infection cause lactose intolerance
lactase susceptible to injury
what is colonic angiodysplasia
submucosal lakes of blood
what causes colonic angiodysplasia
vascular malformation
where is colonic angiodysplasia usually seen
right colon
how is colonic angiodysplasia diagnosed
CT angiography
colonoscopy
how is colonic angiodysplasia treated
embolisation
endoscopic ablation - cauterising bleeding BVs
surgical resection
what is a complication of cauterising bleeding blood vessels
ischaemia
what are 5 types of colitis
ischaemic collagenous lymphocytic radiation pseudomembranous
how is colitis diagnosed
AXR
stool culture
sigmoidoscopy
Ba enema
how is colitis treated if the cause is IBD
IV fluids
IV steroids
GI rest
what are some s/s colitis
diarrhoea +/- blood abdo cramps dehydration sepsis weight loss anaemia
what causes collagenous colitis
NSAIDs
is collagenous colitis seen grossly
no - microscopic
what is seen in the histology of collagenous colitis
thickened basement membrane (basal lamina of epithelial cells)
intraepithelial inflammatory cells
what are some s/s of collagenous colitis
watery diarrhoea
normal endoscopy
is lymphocytic colitis seen grossly
no - microscopic
is there thickening of BM in lymphocytic colitis
no
are there architectural changes in either of the microscopic colitis’
no
what is seen in lymphocytic colitis
increased intraepithelial lymphocytes
- possibly linked to coeliac
what causes radiation colitis
cancer treatment
what is seen in radiation colitis
telangectasia - thread like read lines on skin
what is seen histologically in radiation colitis
Bizarre stroll cells
bizarre vessels - thick walled
what causes pseudomembranous colitis
broad spectrum antibiotics that clear normal flora in colon causing subsequent C. Diff attack
what toxins are produced by C diff
toxin A and B
what is the treatment of pseudomembranous colitis
asymptomatic - none metronidazole \+ vancomycin if severe may need colectomy may be fatal
what are the s/s of pseudomembranous colitis
diarrhoea + bleeding
what is seen in pseudomembranous colitis
patchy membranes stick to mucosa throughout colonic wall
volcano like fibrinopurulent exudate lesions
flame thrower like
what are the 4 Cs associated with C diff infection
ciprofloxacin
clindamycin
co-amoxiclav
cephalosporins e.g. ceftriaxone
