5. Colorectal Disease Flashcards
What is an inflammatory cause of bowel urgency
Proctitis
Coffee brown vomit indicator of?
UGIB
Fresh red vs dark red blood in stools
Fresh red means more recent, severe
What can cause Tenesmus
IBS or IBD- Incomplete emptying
Can be IBS or IBD- due to inflm of rectum pushing up tgt.
May be tumor- DRE to feel for lump
Weight loss in colorectal disease likely due to
Inflmtn or neoplastic
What is Thomas’ sign
ampullary carcinoma- steatorrhea + melena - silver stool
Tx for IBS
FODMAP diet
What diseases suggest increase likelihood of IBD
Diabetes, thyroid, RA, Ank spond, psoriasis- (immune mediated inflammatory disorder)
How does smoking affect risk of CD and UC
Smoker more likely to get CD but decreases UC risk while smoking, doubles after quitting smokinng
What drugs may cause microscopic colitis, what is common Px and which pop is it more common in
antidepressants like SSRIS and PPIs like Lansaprazole, profuse water diarrheoa, more common in older women
Tx for microscopic colitis
budesonide
In what disease can dairrheoa be exacerbated by alcohol
IBS
What is one parasitic cause of diarrheoa in travellers
amoebiasis
What is a histological finding in coeliac disease and what other tests can be done
- Lymphocytes in villi and epithelium
-Anti-TTG (if gluten has been taken) - Gastroscopy @ duodenum
Red flag for colon cancer
Change in bowel habit over age of 50
Another AID common in IBD pts
Hyperthyroidism-
heat intolerant, losing weight, horrible diarrhoea
Dx and Tx for SIBO
Rifaximin course- see if it resolves. Lactulose can see if bacteria is metabolising but not very specific
Sx and Tx of Bile Acid Malabsorbtion
- Secretory Diarrhoea, Steatorrhoea
- Colestyramine
Where is B12 absorbed
TI
What tumours may cause diarrheoa
NETS - due to carcinoid syndrome, serotonin is produced. If meta to liver, may have diarrheoa, wheezing, hot flushes
General Ix for Diarrheoa
- coeliac serology on almost all pts esp those young
- FC to exclude CD or UC
- Qfit - above 10 cant exclude cancer if hv symptoms , need to do colonscopy
- CT colonoscopy
- CT CAP esp if hv weight loss
SB MRI for intestinal CD- hyper enhanced or narrowed
5 Yr intermmitent Sx, 3/day, mushy and hard rock stool alternating, FC <20 - likely Dx and possible other Sx
- Mixed type IBS
- Abd pain better when move bowels
- Sx worse on bread, milk, tomatoes and diet drinks
6mo mushy stools, 4.day on bad say, BS=6, Normal 1 EOD, BS-4
No nocturnal urgency
Weight loss
Assoc abdominal pain
Pain better when bowels moved
Worse with bread
Likely Dx?
Other Sx?
PMHx?
- Coeliac, Dematitis herpetiformis- rash on arms, knees, assoc with coeliac
- FMhx thyroid
6mo prog fluffy stools
7/day BS=6
Urgency and 2 ep incont
Bleeding mixed in stool
Overnight x2 /2 weeks
Weight loss
Rash on shins
FC >2000
Anaemic
Likely Dx?
Ix and Obs?
- Low ani-TTG
Erythema nodosum - rash on shins, may be in IBD
80+ yo
4 wk explosive watery diarrheoa
Bad - 4 day , BS=7
2 ep incont
Ondanston 4mg TDS
Cocodamol
Likely Dx?
XR appearace?
FC, RBC and anti-TTG?
- Drugs can lead to overflow diarrhoea- slow bowel movement- impacted stool
- Speckled appearrance on X ray
- Low FC
- Slightly anaemic,
- Low anti-TTG
2mo light grey porridge like stools
Diff to flush smelly
Oil droplets
Prev alc dep
Recurrent abd pain
Likely Dx?
Ix?
Tx?
- Pancreatitis (calcified) , possibly due to alcohol
- BM= 18
- Vit ADEK all low
- Faecal elastase low pancreatic exocrine insufficient BUT may give false +ve in very water diarrheoa
- Usually give creon as tx
64 YO male
1 mo abd pain
Worse 1-2 h after eating
Eat small meals
Incr stool freq 2-3 day
Current smoker, prev MI and TIA
No weight loss
Mesenteric ischemia- stenosis in gut
Factors that increase the risk of bowel cancer
Smoking, alcohol, increased BMI, red/processed meat, TIIDM
Polyposis related colorectal cancer syndrome vs nonpolyposis
Serrated polyposis syndrome vs Lynch syndrome
3 pathways to CRC
Adenoma-cancer (70-90%), chromosomal instability from APC mutation then RAS activation or loss of TP53
Serrated neoplasia (10-20%), primary RAS/ RAF mutations followed by CPG island mutation
Microsatellite instability (2 -7%), Germline mutations in MMR genes (MSH2,6, MLH1,3, PMS 2,6) - Lynch syndrome
Sx of CRC
Occult or overt rectal bleeding
Change in bowel habit
Anaemia
Abd pain
MAY BE ASx
Dx for CRC
- Colonoscopy + pathology (staining for hist subtype, grading, invasion etc. , can confirm presence of high grade dysplasia +tumour based marked, MSI)
- CT CAP for staging
- MRI (if at rectum) , required for loco-regional rectal cancer staging
- CT colonoscopy for incomplete/ inadequate colonoscopy, old patients etc.
How to manage early polyp cancer
Via en-bloc endoscopy like EMR / SED during endoscopy
General Mx for CRC
- Surgery
- Chemo/radiotherapy
Chemoprophylaxis for lynch syndrome pts
Aspirin
When should colonoscopy be oferred to the public fo bowel cancer screening
> 55yo, or occult blood in stool, or IBD
Sx of LGIB
PR bleeding, haemochezia ( passage of altered blood and stool), breathlessness, headache, cheat pain and fatigue ( 4 Sx of anaemia), and dizziness, blackout, collapse ( 3 Sx of shock)
PMHx for LGIB
Diverticular disease, chronic liver disease, recent surgery/endoscopy
What drugs may increase risk of LGIIB
DOACs, warfarin
Bloods for LGIB
FBC, U and E, LFT, clotting, lactate
Causes of LGIB
Diverticular bleeding ( most common for acute), haemorrhoids, anal fissures, ( subacute/chronic)
angiodysplasia, IBD, rectal ulcers,
rectal polapse, rectal varices, colorectal cancer, post-polypectomy, radiation colitis/ proctitis
Dx of LGIB
Colonoscopy
CT angiogram ( 1st line if pt shocked), catheter angiography with embolisation should be performed.
Colonoscopy if pt shocked but CT angiogram not clear
What score to classify LGIB, and what is the benchmark, what are the factors
Oakland score, <= - minor bleed, discahrge w/ OP Ix, >8 - major bleed, hopsitalisation for assess., resusc and Ix
Factors include Age, gender, previous LGIB adm, DRE findings, HR, SBP, Hb
Mx of LGIB
Endoscopic - clips as first line +/- Adr. injxn, heater prob, heamosprat as last resort, APC for coagulation therapy, Thrombin/glue injxn
Interventional radioolgy- embolisation of bleeding vessels with coils, liquid agents and particals, but ischaemia possible in up to 24%
Surgery
Sx of IDA
May be aSx, or have breathlessness, fatigue, angina, angular stomatitis, koilonychia, restless leg syndrome, papophagia
Pathological causes of IDA -
Neoplasia, IBD, peptic ulcer, vascular malformation eg. angiodyplasia, haematuria, gynaecological blood loss
Coeliac and Crohn’s, Hypochlorohydria -atrophic gastritis, H. pylori and gastrectomy/bypass
Is IDA macro or micro cytic and hypo or hyper chromic
micro, hypo
What should be first measured for IDA and what are the caveats
Ferritin most specific, true IDA if ferritin low, but may be elevated in inflmt states/ infxn
Iron studies- what should be seen in IDA
Decreased serum iron, transferrin saturation, increased serum transferrin, soluble transferrin receptor and TIBC, ferritin decreased or normal
What to do if Dx of IDA is in doubt
Trial oral iron for 2-4 weeks, if Hb rise >10g/L in 2 weeks, suggestive of IDA
Ix in IDA
Bi-directional endoscopy in men and post meno women, CT colonoscopy if multiple co-morbidities
Urinalysis for microscopic haematuria, coeliac serology, Ix of small bowel if no other cause found
Colour of rectal bleeding
Bright red
How can SoBoE be present in pts with CRC- bloods??
Pts may have microcytic anaemia
First line investigation in pt with microcytic anaemia and suspected ca
endoscopy first, then colonoscopy if nothing found
Where is squamous cell cancer found in the GI tract
only anus
What are the categories for staging CRC
- T
- T1 - mucosa/submucosa
- T2 - muscle
- T3- serosa
- T4- outside
- N
- 1-3
- 3-7
- > 7
- M
- 0/1 if there’s metastasis
Tx for rectal ca
Resection - may need to remove sigmoid colon
When should adjuvant chemotherapy be given for caecal cancer
for those fit enough, or node positive, or bad Duke’s B (T4, poor diff., lymphovasc inv. etc.)
Side effect of CAPOX
Peri neuropathy
Ix for rectal cancer
Will need full colonoscopy for distal polyps
- Look for resection margin → TMA
- May need radiotherapy pre-operatively to down stage disease and chemo to stop widespread of ca
- Neoadjuvant (preop) radioT can result in 30% red. in local RR
- No overall mort. red. for any XRT ref.
- Long course given prior to pt w/ any high risk features
- Short course don’t get chemo
Stage T3/4, N+ M1 is stage what cancer? how to treat?
Stage 4 ca, just palliative intent with Sx control ( pain, profuse diarrheoa, obstructive sx)
- Can resect obst, put stent to reat obst, and bring out defunctioning stomas laprascopically
What to do for qFIT +ve pts who are older ( check benchmark)
Colonoscopy to rule out cancer
Observation vs resection for adenocarcinoma
- High risk factors
- Poor diff,
- Venous invasion
- Lymphatic inv,
- distance to deep margine <1mm,
- If none of these than >99% cured by polypectomy alone ( can consider cured for polyp cancer once removed)
What should be done if pedunculated polyps is found on colonoscopy
Usually excise it with snare polypectomy then do histology
Dx of anal fissures or haemorrhoidal bleeding
Haemorrhoidal bleeding is bright red and occurs during or after defecation. Proctoscopy can be used to make the diagnosis, but individuals who have altered bowel habit and those who present over the age of 40 years should undergo colonoscopy to exclude coexisting colorectal cancer. Anal fissure should be suspected when fresh rectal bleeding and anal pain occur during defecation.
Risk
