Case 14: Per rectum bleeding Flashcards
what can cause diarrhoea without blood loss
norovirus
coeliac
hyperthyroidism
IBS
lactose intolerance
bile acid diarrhoea
constipation with overflow diarrhoea
laxative abuse
giardia infection
pancreatic exocrine insufficiency
what can cause diarrhoea with the potential of blood loss
IBD
colorectal cancer
severe c.diff
diverticulitis
ischameic colitis
shinga toxin producing e.coli infection
shigella infection
what can cause visible blood loss without diarrhoea
haemorrhoids
perianal fissure
how long does norovirus typically last
24-72hrs
how long does giardia infection typically last
many weeks
what is giardia and how does it present
parasitic infection
foul smelling diarrhoea, bloating, cramping, abdominal pain and weight loss
route of infection with giardia
exposure to contaminated flood, water of faeces
1st line treatment for giardia
metronadiazole
what is pancreatic exocrine insufficiency
reduced secretion pancreatic enzymes meaning food cannot be broken down and absorbed
presentation of pancreatic exocrine insufficiency
weight loss
bloating abdominal pain
foul smelling diarrhoea
steatorrhea
causes of pancreatic exocrine insufficiency
pancreatitis
malignancy
previous surgery
diabetes
CF
rarer causes of ischaemic colitis in younger patients
sickle cell
vasculitis
what type of organism is shigella
bacteria
how is shigella spread?
contact with contaminated food, water or facaes
can be spread by sexual contact with infected person
presentation of shigella
bloody diarrhoea
crampy abdominal pain
fever
how long does shigella typically last
normal= symtoms resolve within one week
how should shigella be treated in immunocompromised patients
previously ciprofloxacin but due to antibiotic resistance azithromycin now used
how is shiga toxin producing e.coli spread
contaminated food, water or faeces
presentation of shiga toxin producing e.coli
damages bowel wall causing abdominal pain, bleeding and diarrhoea
treatment of shiga toxin producing e.coli
not treated with antibiotics due to risk of haemolytic uraemic syndrome (more common in children)
what is an anal fissure
small tear in the lining of the anal canal
presentation of anal fissure
sharp pain on defecation
bright red blood in stool/on wiping
what % of those with IBD have an affected 1st degree relative
10-25%
relation of smoking and IBD
is a risk factor for crohns
masked the symptoms of UC- smoking cessation can bring about disease
extra intestinal manifestations occur in what % of IBD patients
20-40%
what are these extra intestinal manifestations
arthritis
skin lesions
eye disease
liver disease
steps to take if your 1st differential is IBD
send blood tests
do feacal calprotectin (FCP) and stool cultures
urgent outpatient referral to gastroenterology
which diarrhoea drug is contraindicated in IBD
loperamide
can increase the risk of bowel dilation and toxic megacolon in IBD
aside from IBD, what other conditions can cause an increase in faecal calprotectin
severe c.diff mediated diarrhoea
PPIs
severe diverticulitis
acute appendicitis
ischaemic colitis
changes to potassium, urea and albumin in chronic diarrhoea
low K+ due to loss from GI tract
raised urea due to dehydration
low albumin due to chronic inflammation causing increased albumin degradation
other causes of hypokalaemia
vomiting
loop/thiazide diuretics
mineralocorticoid excess
what issues can hypokalaemia cause
cardiac arrythmias
muscle cramps
hypokalaemia ECG changes
T wave flattening
ST depression
U waves
what is considered a fluid challenge
500ml of 0.9% sodium chloride over less than 15 mins
never give K+ with this as it can cause ventricular arrhythmias and death
what 2 situations would you always give IV steroids despite infection
if you suspect acute adrenal crisis
if they are on long term steroids and now cannot take them orally (missing a dose may cause adrenal crisis)
3 complications of UC (from most to least likely)
iron deficiency anaemia
colorectal cancer
primary sclerosing cholangitis
what drug can cause rectal ulceration
nicorandil (anti-anginal drug)
what are the 5 cardinal features of acute inflammation
pain
swelling
redness
heat
loss of function
pathophysiology of acute inflammation
histamines and prostaglandins cause vasodilation of arterioles resulting in local hyperaemia
this causes redness and heat
increase in capillary permeability causes fluid exudate from the vascular space into the interstitial space
this results in pain, oedema and reduced movement
neutrophils move from blood vessels to the affected area by marginating along the endothelium before attaching to the endothelial wall via adhesion to emigrate thought the wall towards the affected area
here the neutrophil does phagocytosis
the eventual potential outcomes of acute inflammation
complete resolution
fibrosis and formation of scar tissue
chronic inflammation
formation of an abscess
what is an abscess
localised collection of pus walled off by granulation tissue
what does the pus contain in an abscess
necrotic tissue
neutrophils
pathogens
it is usually under pressure as enzymes continually break down proteins which increase oncotic pressure (this causes pain)
management of an abscess
incision and drainage
if it is within a cavity (peritoneal) it may be appropriate to radiologically insert a drain to remove the pus
what is necrotising fasciitis
subset of aggressive soft tissue and skin infections that cause necrosis of the muscle fascia and subcutaneous tissues
clinical features of necrotising fasciitis
skin necrosis
skin crepitus (air bubbles under skin- gas forming organism)
septic shock
mortality rate of necrosting fasciits
it leads to sepsis
20% mortality
management of necrosting fasciits
urgent debridement- removal of surface debris, slough, and infected matter from the wound bed
causes of perianal abscess
blocked glands in the anal area
infection of an anal fissure
STD
trauma
risk factors for perianal abscess
diabetes
anal sex
chemotherapy
IBD
corticosteroids
weakened immune system (HIV/AIDS)
what are haemorrhoidal cushions
highly vascular structures around the rectum that help with stool control and continence
what are haemorrhoids
when these cushions get inflamed, swell and start prolapsing downwards under pressure
what are internal haemorrhoids
above dentate line (within the anal canal)
usually painless
can present with bright red rectal bleeding associated with bowel movements
blood coats the outside surface of the stool (haematochezia)
what are external haemorrhoids
below dentate line
prolapses outwards and is palpable by patient
usually painless
usually painless unless they become acutely thrombosed (swelling and pain)
grades of internal haemorrhoids (1-4)
1= no prolapse of the mucosa
2= haemorrhoid prolapses on bearing down but reduced spontaneously
3= haemorrhoid prolapses on bearing down but requires manual reduction
4= haemorrhoid prolapses but cannot be reduced
medical management of grade 1-2 internal haemorrhoids
lifestyle- high fibre diet
laxatives
rubber bad ligation of internal haemorrhoids using proctoscope or endoscope
surgical management of grade 2-3 internal haemorrhoids
rafelo procedure (radiofrequency ablation of haemorrhoids under local anaesthetic)- uses radiofrequency energy to cauterise the blood supply causing it to retract
haemorrhoidal artery ligation operation (HALO)- ultrasound probe identifies the feeding haemorrhoidal artery which is the ligated with a suture to cut the blood supply off causing thrombosis, fibrosis and retraction of the haemorrhoid
surgical mama gent of grade 4 internal/external haemorrhoids
excisional haemorroidectomy to physically exercise the haemorrhoid either with energy device or stapler
colorectal cancer suspicion endoscopy referral
over 40 with unexplained weight loss and abdominal pain
over 50 with unexplained rectal bleeding
over 60 with iron deficiency anaemia or changes in bowel habits or test show occult blood in faeces
what position is perianal abscess typically
3 o clock
9 o clock
what position is perianal fissure typically
12 o clock
6 o clock
what is the pain like with perianal fissure
sharp glass-like pain which radiates up into the rectum on defecation
common causes of perianal fissure
mechanical stretching (such as constipation)- usually seen at 12/6oclock
atypical causes of perianal fissures
IBD
immunocompromised status
carcinoma
TB
these can cause tears at any point around anus
what typically surrounds a perianal fissure on examination
white scar tissue
treatment of perianal fissure
first give stool softeners and/or laxatives to reduce straining
GTN ointment (0.4%), stool softeners, botox to the anal sphincter to relax it and reduce spasm
surgery where both conservative and medical have failed- do lateral sphincterotomy where the interval sphincter is divided to reduce sphincter spasm
risks of lateral sphincterotomy
high risk of incontinence to both flatus and faeces
features of derv inflammatory bowel disease
pyrexia
tachycardia
visible blood in stool
spontaneous bleeding and ulceration on endoscopy
