Colorectal I Flashcards
What positions do you find haemorrhoids in? [3]
11, 7 and 3 o’clock
A fistula is defined as an abnormal connection between two epithelial surfaces.
What are the two most common causes of fistulae? [2]
diverticular disease and Crohn’s.
Describe how you treat fistulae if:
- No IBD or distal obstruction? [1]
- High-output is excessive? [2]
- Secondary to Crohns? [1]
No IBD or distal obstruction: Conservative management
- High-output is excessive: octreotide (reduces pancreatic secretions); TPN
- Secondary to Crohns: drain acute sepsis; seton placement
Anal cancer is linked with an infection of which virus? [1]
HPV
Describe the difference in presentation of Lynch syndrome (HPNCC) and FAP [1]
Lynch syndrome:
- causes bowel cancer without adenomatous polyps
FAP:
- Poylpoidal
Describe the difference in screening for Lynch syndrome (HPNCC) and FAP [1]
Lynch: colonoscopy every 1 or 2 years from 25
FAP: annual sigmoidoscopy from 15 yrs – if no polyps - every 5 years; if polyps - resectional surgery
FAP has a 90% of having polyps where? (outside of large bowel) [1]
Duodenum
How do you differentiate between a strangulated and incarcerated indirect inguinal hernia? [2]
If a hernia cannot be reduced it is referred to as an incarcerated hernia - these are typically painless
if the patient had systemic features - would indicate strangulated and normally painfull
How would Meckel’s diverticulitis present? [5]
- most common: painless rectal bleeding
- age < 2 years
- passage of bright red blood per rectum (haematochezia)
- intractable constipation (obstipation)
- It is clinically indistinguishable from appendicitis: Right sided pain
When do you perform an abdomino-perineal resection of a colorectal tumour? [2]
When do you perform an anterior resection? [2]
AP resection is the preferred surgical option for tumours < 5 cm from the anal verge or involving the distal 2/3 of the rectum
Anterior resection is the preferred surgical option for tumours >8 cm from the anal canal or involving the proximal 1/3 of the rectum.
You suspect a patient has a biliary pathology, what is the first line of imaging used to diagnose this? [1]
Ultrasound
Bowel sounds are helpful in suspected obstruction. Describe how this can be helpful [2]
High pitched (tinkling): obstruction
Absent: ileus (non-mechanical obstruction)
Describe a way of classifying bowel obstructions [3]
Name three suggestions for the each of the above [9]
Extramural: block bowel from outside
- Adhesions (congenital or aquired)
- Hernia
- Volvulus (caecal; sigmoid; small bowel)
- Compression from lymph nodes
Intramural: blockage from within the wall
- Tumours (adenocarcinoma, GISTs, lymphoma, leiomyosarcoma)
- Strictures bowel has narrowed due to: diverticular, ischaemic, IBD, post op,
- Intussusecption (wall of bowel moves into itself & blocks itself, most commonly at terminal ileum and caecum)
Intraluminal: within the wall
- Gall stones
- Bezoar
- Foreign body
- Meconium
What is the imaging that is the investigation of choice for bowel obstruction? [1]
State other imaging used [1]
CT: imaging of choice;
XR
What is gastrograffin AXR? [1]
When is its use indicated? [1]
Gastrograffin:
* Water soluble contrast for small bowel adhesive obstruction.
* If gastrograffin has passed into colon then suggests that will resolve (if not then surgery is indicated)
What’s a pneumonic for remembering the causes of small bowel obstruction?
“HANG IVs”
Hernias 2%
Adhesions (from previous surgery with formation of intra abdominal adhesions, commonly colorectal and gynaecological surgery)
Neoplasms (malignant, benign, primary or secondary) (5%)
Gallstone ileus
Intussusception
Volvulus
Strictures (eg Crohn’s disease (6%), ischaemia)
Explain what VBG readings would you suspect with a patient with bowel obstruction? [2]
Metabolic alkalosis due to vomiting stomach acid
What are the indications for surgery for SBO? [2]
Bowel compromise (e.g. ischaemia, perforation, necrosis), generally occurring in complete bowel obstructions
Surgically correctable causes (e.g. volvulus, incarcerated hernia, gallstone ileus, foreign body ingestion, tumour)
How would you surgically treat SBO? [4]
- Exploratory surgery in patients with an unclear underlying cause
- Adhesiolysis to treat adhesions
- Hernia repair
- Emergency resection of the obstructing tumour
- If surgery is being undertaken, patients should have antibiotic prophylaxis
If surgery is indicated for SBO, patients should be given antibiotic prophylaxis of which antibiotics? [3]
cefoxitin, or ampicillin plus gentamicin
What is A?
Anal abscess
Anal fissure
Haemorrhoid
Anal fistula
What is A?
Anal abscess
Anal fissure
Haemorrhoid
Anal fistula
An anal fissure is a superficial tear in the skin distal to the dentate line