GI 2 Flashcards
What are some mechanisms of intestinal obstruction?
Mechanical
True (intraluminal/extraluminal)
Functional - paralytic ileus
What can cause intestinal obstruction?
Tumour - carcinoma, lymphoma
Diaphragm disease
meconeum ileus
gallstone ileus
crohn’s
diverticulitis
hirschprung’s
adhesions (most common)
volvulus
How does small intestinal obstruction present?
pain - colicky then diffuse, pain higher than in large bowel obstruction
profuse vomiting that follows pain
less distension than LBO
nausea
tenderness = strangulation
How would you investigate a SBO?
Abdo X-ray - partial SBO = gas throughout the abdomen and into the rectum
complete SBO = no distal gas, staggered air-fluid levels
FBC
Urea
Electrolyte panel
Abdo CT
How would you a treat a SBO?
Emergency laparotomy plus fluid resus
Preoperative antibiotic prophylaxis - ampicilin + gentamicin
morphine
How would a large bowel obstruction present?
on av. 5 days of symptoms - present slower and later than in SBO
abdo pain that is more constant than in SBO
bowel sounds normal then quiet
palpable mass
late vomiting
constipation
fullness/bloating/nausea
How would you investigate a LBO?
FBC
serum electrolytes
renal function
serum amylase/lipase
erect chest x-ray
plain abdo x -ray- gaseous distension of large bowel, kidney shape seen in volvulus
How would you manage a LBO?
emergency surgery
What causes LBO?
colorectal malignancy
volvulus
What is a pseudo-obstruction?
clinical picture mimicking obstruction but with no mechanical cause
What are some causes of pseudo-obstruction?
intra-abdominal trauma
pelvic, spinal and femoral fractures
postoperative states
intra-abdominal sepsis
pneumonia
drugs (opiates, antidepressants)
metabolic disorders (electrolyte disturbances, malnutrition)
What are the 3 main types of bowel ischaemia?
acute mesenteric ischaemia
chronic mesenteric ischaemia (intestinal angina)
ischaemic colitis (chronic colonic ischaemia)
Where is blood supply to colon come from?
What are watershed areas which are most susceptible to ischaemia?
inferior and superior mesenteric arteries
splenic flexure and caecum
What is acute mesenteric ischaemia? What are the causes?
bowel ischaemia affecting the small bowel
caused by superior mesenteric thrombosis
How does acute mesenteric ischaemia present?
Acute severe abdominal pain - constant, central or around right iliac fossa
No abdo signs
Rapid hypovolaemia - shock
How would you investigate ischaemic bowel disease?
CT - first line
sigmoidoscopy or colonoscopy
FBC
Chemistry panel - acidosis, uraemia, elevated creatinine
Coag panel - underlying prothrombotic disorder
ABG/lactate level
ECG - arrthmias or acute infarct that may be cause
Erect CXR - free air if perforation present
Abdo x-rays
How would you manage iscahemic bowel disease when there is no sign of infarction, perforation or peritonitis?
Supportive - NG tube, NBM, O2
Empiric Abx - ceftriaxone and metronidazole
SMA Embolus - open embolectomy or arterial bypass +/- bowel resection
Papaverine - antispasmodic
Chronic mesenteric ischaemia - medical optimisation + surgival systemic mesenteric bypass
Non-acute colonic ischaemia - segmental colectomy
Non-acute colonic ischaemia - segmental colectomy
What are the causes/RFs of Ischaemic Colitis?
Low flow in the inferior mesenteric artery territory
thrombosis
emboli
decreased cardiac output
drugs - oestrogen, antihypertensives, vasopressin
surgery
vasculitis - SLE, sickle cell
Coag disorders
COCP
How would ischaemic colitis present?
sudden onset lower left side abso pain
bright red blood without diarrhoea
signs of shock
What are some causes of haemorrhoids?
constipation
diarrhoea
congestion - pelvic tumour, pregnancy, portal hypertension
anal intercourse
When do haemorrhoids become painful?
Only painful if they are below the dentate line - protrude and are gripped by the anal sphincter
How would you classify internal haemorrhoids?
1st - remain in rectum
2nd - prolapse through the anus on defection but then reduce
3rd - prolapse but can be reduced manually
4th - remain persistently prolapsed
How would haemorrhoids present?
bright red rectal bleeding - on tissue or drips onto toilet
mucus discharge
pruritus ani
severe anaemia
change in bowel habit
How would you investigate haemorrhoids?
anoscopic examination
colonoscopy - exclude serious pathology such as IBD
FBC
How would you manage haemorrhoids?
25-30g of fibre
bowel habit advice
rectal hydrocortisone
rubber band ligation or sclerotherapy
surgical haemorroidectomy
What are some causes of anal fistula formation?
perianal sepsis
abscesses
crohns
TB
diverticular disease
rectal carcinoma
How would an anal fistula present?
pain
discharge
pruritus ani
systemic abscess
How would you treat an anal fistula?
fistulotomy and excision
drain abscess with abx if infected
What is a fissure-in-ano?
painful tear distal to dentate line
90% posterior
10% anterior most likely following childbirth
What are some causes of fissure-in-ano?
hard faeces
childbirth
syphilis
herpes
trauma
crohns
anal cancer
How would you treat fissure-in-ano?
diet - fibre and fluids
lidocaine ointment + GTN ointment or topical diltiazem
botox
What are the 3 types of IBS?
IBS-C - constipation
IBS-D - diarrhoea
IBS-M - constip and diarrhoea
What are some intestinal presentations of IBS?
ABC + 2 more
Abdo pain/discomfort
Bloating
Change in bowel habit
2 more of =
urgency
incomplete evacuation
abdo bloating/distension
muscous in stool
worsening symptoms after food
What are some extra-intestinal presentations of IBS?
urinary frequency, urgency, nocturia
bac pain
joint hypermobility
fatigue
nausea
What are some red flag symptoms to be aware when investigating IBS?
unexplained weight loss
PR bleed/blood in stool
FHx of bowel or ovarian cancer
change in bowel habit >50
rectal/abdo mass
raised inflamm markers
anaemia
What is the ROME IV criteria for IBS?
Recurrent abdominal pain, on average, at least 1 day/week in the last 3 months, associated with two or more of the following criteria:
i) Related to defecation
ii) Associated with a change in frequency of stool
iii) Associated with a change in form (appearance) of stool.
How would you investigate IBS?
diagnosis of exclusion
FBC - investigate anaemia
Stool study - rule out infection
Anti-endomysial & tTG - rule out coeliac
abdo x-ray - obstruction
colonoscopy - IBD
How would you manage IBS?
Constip
i) laxative (lactulose)
ii) antispasmodics (dicycloverine, peppermint oil)
iii) SSRI (citalopram)
Diarrhoea
I) loperamide
ii) dicycloverine
iii) TCA - amitriptyline
What are some differentiating factors between IBS and IBD?
IBD more systemic :
Fever Extra-intestinal symptoms Melena Weight loss Mouth ulcers
What is diverticulosis, diverticular disease and diverticulitis?
Diverticulosis = presence of diverticula
Diverticular disease = diverticula are symptomatic
Diverticulitis = inflammation of a diverticulum
What are some causes of diverticulitis?
low fibre diet
Obesity
Smoking
NSAIDs
Over 50
How would diverticulitis present?
Asymp in 95%
Intermittent left iliac fossa pain
Erratic bowel habit
Constipation
*similar to appendicitis but left sided
febrile
tachycardia
tendernessand guarding on left side
What are some complications of diverticular disease?
perforation
fistula formation
- into bladder = dysuria
- into vagina = discharge
intestinal obstruction
bleeding
mucosal inflammation
How would you investigate diverticular disease?
FBC - polymorphonuclear leucocytosis
CT colonography
Abdo x-ray
How would you treat diverticular disease?
Dietary - fibre
Amoxicillin
Paracetmol/Tramadol/Morphine
Low residue diet - refined bread, white rice, vegetable without pulp
endoscopic embolization
surgery
What is Meckel’s diverticulum?
most common congenital abnormality of GI tract
diverticulum projects from the wall of the ILEUM
can secrete HCL = peptic ulcers
Where is the appendix located?
McBurney’s point = 2/3rds of the way from the umbilicus to the ASIS
What are the causes of appendicitis?
faecolith
lymphoid hyperplasia
filarial worms
How does acute appendicitis present?
pain umbilical region that migrates to the right iliac fossa (McBurney’s)
anorexia
nausea and vomiting
constipation
fever
How would you investigate acute appendicitis?
FBC - mild leucocytosis
abdo and pelvic CT scan
pregnancy test - rule out ectopic
How would you treat acute appendicitis?
appendectomy
IV abx - cefoxitin
