GI Flashcards
commonest cause of LBO
colorectal carcinoma
commonest cause of SBO
adhesions
most common site of a carcinoid tumour
appendix
what does free air on abdo film suggest
perforation
when to refer for 2 wk wait suspected gastro cancer
(urgent endoscopy)
all px 55+ w weight loss + either:
- upper abdo pain
- reflux
- dyspepsia
ix + mx of perianal abscess
urgent MRI to see extent + to see if fistula
drainage via EUA (rectal exam under anaesthesia)
started on intravenous antibiotics e.g. ceftriaxone + metronidazole.
draining seton if complex
Familial adenomatous polyposis (FAP) features
Mutation in the adenomatous polyposis coli (APC) gene
AD
Px dev hundreds of adenomatous polyps in their teens - develop colorectal cancer by their 20s -> prophylactic proctocolectomy
High risk of developing duodenal cancer -> regular endoscopic surveillance.
Hereditary non-polyposis colorectal cancer (HNPCC)/Lynch syndrome features
mutation in the mismatch repair genes MLH1/MSH2
AD
80% risk of developing colorectal cancer by their 30s. Polyps turning to carcinoma occurs more rapidly.
There is increased risk of gastric, endometrial, breast, and prostate cancer.
Regular endoscopic surveillance.
triad of acute mesenteric ischaemia
severe abdo pain
unremarkable abdo exam
shock
what is achalasia
Failure of oesophageal peristalsis and of relaxation of the lower oesophageal sphincter (LOS) due to degenerative loss of ganglia from Auerbach’s plexus
i.e. LOS contracted, oesophagus above dilated.
Achalasia typically presents in middle-age and is equally common in men and women.
clinical presentation of achalasia
dysphagia of BOTH liquids and solids
typically variation in severity of symptoms
heartburn
regurgitation of food
may lead to cough, aspiration pneumonia etc
malignant change in small number of patients
ix for achalasia
oesophageal manometry
- excessive LOS tone which doesn’t relax on swallowing
- most important diagnostic test
barium swallow
- shows grossly expanded oesophagus, fluid level , tapers at the lower oesophageal sphincter
- ‘bird’s beak’ appearance
chest x-ray
- wide mediastinum
- fluid level
tx of achalasia
pneumatic (balloon) dilation is increasingly the preferred first-line option
surgical intervention with a Heller cardiomyotomy should be considered if recurrent or persistent symptoms
intra-sphincteric injection of botulinum toxin is sometimes used in patients who are a high surgical risk
drug therapy (e.g. nitrates, calcium channel blockers) has a role but is limited by side-effects
what can c diff infection cause
pseudomembranous colitis
mx of c diff infection
first-line therapy is oral vancomycin for 10 days
second-line therapy: oral fidaxomicin
third-line therapy: oral vancomycin +/- IV metronidazole
ix c diff
is made by detecting C. difficile toxin (CDT) in the stool
C. difficile antigen positivity only shows exposure to the bacteria, rather than current infection
most common abx to lead to c diff
cephalosporins
first line diagnostic test for small bowel bacterial overgrowth syndrome
hydrogen breath testing
abx tx for small bowel bacterial overgrowth syndrome
rifaximin
what is the most common cause of infectious intestinal disease in the uk (give me a bacteria)
campylobacter jejuni
(gram -ve bacillus)
features of campylobacter jejuni
faecal-oral route
incubation period 1-6 days
- prodrome: headache, malaise
- diarrhoea: often bloody
- abdominal pain: may mimic appendicitis
how to differentiate CROHNS from UC
Crohns NESTS
N – No blood or mucus (these are less common in Crohns.)
E – Entire GI tract
S – “Skip lesions” on endoscopy
T – Terminal ileum most affected and Transmural (full thickness) inflammation
S – Smoking is a risk factor
Crohn’s is also associated with weight loss, strictures and fistulas.
get increased goblet cells
how to differentiate UC from CROHNS
U… C… CLOSE UP
C – Continuous inflammation
L – Limited to colon and rectum
O – Only superficial mucosa affected
S – Smoking is protective
E – Excrete blood and mucus
U – Use aminosalicylates
P – Primary sclerosing cholangitis
get crypt abscesses
mx of UC mild/moderate
First line: aminosalicylate (e.g. mesalazine oral or rectal)
Second line: corticosteroids (e.g. prednisolone)