Session 7- Distal GI pathology Flashcards
pathophysiology of diarrhoea
unwanted substance in gut stimulates secretion and motility
colon is overwhelmed and cannot absorb the quantity of water it recieves from ileum
secretetory diarrhoea
toxin in gut lumen therefore water is secreted inside. Too much secretion of ions
persists despite fasting
increased stool osmolality
osmotic diarrhoea
water moves into gut becaue there are molecules present that have a high osmotic pressure.
stops when fasting
why do you get diarrhoea if you have lactose intolerance
as the lactose isnt broken don it acts as a osmotic pressure drawing water in and the gets fermented in Large intestine
constipation
hard stools
difficulty passing stools
inability to pass stools
risk factors of constipation
female
certain meds
low levels of activity
age
treatments of constipation
psychological support
increased fluid intake
increased activity and fibre
laxatives
what is the appendix
diverrticulum off the caecum
how does the appendix differ from the colon structuly
has a complete longitudinal layer of muscle whereas colon has incomplete bands called teniae coli
blood supply to appendix
comes up through mesentery- mesoappendix- from the ileocolic branch of SMA
why is the location of the appendix important
changes the presentation of acute appendicitis
cause if appendicitis
blockage of appendicel lumen creates a higher pressure in the appendix
-this causes venous pressure to rise which blocks arterial supply -> ischeamia
a viral or bacteral infection causes the lymphoid tissue to hypertrophy to the point that they obstruct the lumen
presentation of appendicitis
poorly localised per-umbilical pain
anorexia
nausea/ vomiting
low grade fever
where is pain felt normally in appendicitis
right iliac fossa
where is mcburneys point
2/3 of the way from umbilicus to ASIS
what is rebound tenderness
push into right iliac fossa let go and it should hurt more when let go than when pressure is applied
diagnosis of appendicitis
blood test- raised WBC
history and physical examination
pregnancy test- ectopic preg
treatment if appendicitis
appendectomy - open or laproscopic
what is diverticula
outpouchings of mucosa and submucosa herniate through muscularis layers where nutrient vessels penetrate bowel wall
what causes diverticulitis
increased intra-luminal pressure
what is diverticular disease
when the patientexeriences pain bt there s no inflammaion
what is acute diverticulitis
when the diverticula become inflammed or perforate due t the entrance being blocked by faeces which allows bacterial invasion
uncomplicated diverticulitis
inflammation and small abcesses confined to colonic wall
complicated diverticulitis
larger abceses fistula perforation
symptoms of acute diverticulitis
abdominal pain at site of inflammation
-left lower quadrant
fever
bloating
constipation
haematochezia
signs of acute diverticulitis
localosed abdominal tenderness
distension
reduced bowel sounds
signs of peritonitis
treatment of acute dverticultis
abitibiotcs
fluid resusciation
analgesia
surgery if perforation or large abcesses need to be frained
what is the superior rectal artery a continuation of
inferior mesenteric artery
blood supply to rectum
superior rectal
middle rectal
inferior rectap
where is the start of the anal canal
proximal border of the anal sphincter complex
in what direction does the rectum point
anteriorly
what changes the direction of te rectum
pubo-rectalis
what way doe sthe anal canal point
posteriorly
what are anal cushions
complex netwoek of blood vessels
the anus contains a complex venous plexus which is divided into three areas of tissues and play a role in anal continence
nerve supply to external anal sphincter
pudental nerve
what is the dentate line
junction of hindgut and proctodaeum
what lies above the dentate line
visceral pain receptors
columnar epithelium
what is below the dentate line
somatic pain receptors
stratified squamous epithelia
what are internal haemorrids
above dentate line
caused by loss of connective tissue support
painless
bleed bright red blood
treatment of internal haemorrhoids
hydration
avoid straining
surgery
external haemorroids
below dentate line
swelling of anal cushions which may thrombose
anal fissure
linear tear in the anoderm caused by passing of hard stool
haematochezia
cause of anal fissure
reduced blood flow to anal mucosa
high internal anal sphincter tone
treatment of anal fissure
warm bath medication hydration fibre analgesia
melaena
black tarry stools
offensive smelling - due to hb being altered by digestive enzymes and gut bacteria
causes of maleana
upper GI bleed peptic ulcer disease varicel bleeds oesophageal cancer upper GI malignancy
