Colorectal I

Question 1

What positions do you find haemorrhoids in? [3]

Answer 1

11, 7 and 3 o’clock

Question 2

A fistula is defined as an abnormal connection between two epithelial surfaces.

What are the two most common causes of fistulae? [2]

Answer 2

diverticular disease and Crohn’s.

Question 3

Describe how you treat fistulae if:
- No IBD or distal obstruction? [1]
- High-output is excessive? [2]
- Secondary to Crohns? [1]

Answer 3

No IBD or distal obstruction: Conservative management
- High-output is excessive: octreotide (reduces pancreatic secretions); TPN
- Secondary to Crohns: drain acute sepsis; seton placement

Question 4

Anal cancer is linked with an infection of which virus? [1]

Answer 4

HPV

Question 5

Describe the difference in presentation of Lynch syndrome (HPNCC) and FAP [1]

Answer 5

Lynch syndrome:
- causes bowel cancer without adenomatous polyps

FAP:
- Poylpoidal

Question 6

Describe the difference in screening for Lynch syndrome (HPNCC) and FAP [1]

Answer 6

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

Question 7

FAP has a 90% of having polyps where? (outside of large bowel) [1]

Answer 7

Duodenum

Question 8

How do you differentiate between a strangulated and incarcerated indirect inguinal hernia? [2]

Answer 8

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

Question 9

How would Meckel’s diverticulitis present? [5]

Answer 9

• 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

Question 10

When do you perform an abdomino-perineal resection of a colorectal tumour? [2]

When do you perform an anterior resection? [2]

Answer 10

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.

Question 11

You suspect a patient has a biliary pathology, what is the first line of imaging used to diagnose this? [1]

Answer 11

Ultrasound

Question 12

Bowel sounds are helpful in suspected obstruction. Describe how this can be helpful [2]

Answer 12

High pitched (tinkling): obstruction

Absent: ileus (non-mechanical obstruction)

Question 13

Describe a way of classifying bowel obstructions [3]
Name three suggestions for the each of the above [9]

Answer 13

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

Question 14

What is the imaging that is the investigation of choice for bowel obstruction? [1]
State other imaging used [1]

Answer 14

CT: imaging of choice;
XR

Question 15

What is gastrograffin AXR? [1]
When is its use indicated? [1]

Answer 15

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)

Question 16

What’s a pneumonic for remembering the causes of small bowel obstruction?

Answer 16

“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)

Question 17

Explain what VBG readings would you suspect with a patient with bowel obstruction? [2]

Answer 17

Metabolic alkalosis due to vomiting stomach acid

Question 18

What are the indications for surgery for SBO? [2]

Answer 18

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)

Question 19

How would you surgically treat SBO? [4]

Answer 19

• 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

Question 20

If surgery is indicated for SBO, patients should be given antibiotic prophylaxis of which antibiotics? [3]

Answer 20

cefoxitin, or ampicillin plus gentamicin

Question 21

What is A?

Anal abscess
Anal fissure
Haemorrhoid
Anal fistula

Answer 21

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

Question 22

What does the following best describe?

abnormal tunnel under the skin that connects the anal canal in the colon to the skin of the buttocks

Anal abscess
Anal fissure
Haemorrhoid
Anal fistula

Answer 22

What does the following best describe?

abnormal tunnel under the skin that connects the anal canal in the colon to the skin of the buttocks

Anal abscess
Anal fissure
Haemorrhoid
Anal fistula

Question 23

What FBC / blood film finding would indicate acute diverticulitis? [1]

Answer 23

Polymorphonuclear leukocytosis

BMJ BP: First line invest.

Question 24

Describe the treatment algorithm for acute fissures

Answer 24

1st line: soften stool
- high fibre intak
- Bulk forming laxatives
- lubricants like petroleum jelly

2nd line:
- Glyceryl trinitrate

3rd line:
- topical diltiazem (if headaches from glyceryl trinitrate are too much)

Question 25

Describe the treatment algorithm for chronic anal fissures [3]

Answer 25

**topical glyceryl trinitrate (GTN**) is first-line treatment for a chronic anal fissure **Botulinum toxin** or **sphincterotomy** is used after failure of topical treatment for **8 weeks** *sphincterotomy*: *The operation usually takes about 15 minutes. Your surgeon will make a small cut on the skin near your back passage. They will cut the lower part of the internal sphincter muscle. This will relieve the spasm in the sphincter, allowing a better blood supply to heal the fissure.*

Question 26

almost all diverticula are found in the []

Answer 26

almost all diverticula are found in the **sigmoid colon**

Question 27

Describe two symptoms of complications of diverticulitis [2]

Answer 27

**pneumaturia** or **faecaluria** may suggest a **colovesical fistula** **vaginal passage** of **faeces** or **flatus** may suggest a **colovaginal fistula**

Question 28

What might an AXR show in diverticulosis? [3]

Answer 28

AXR: may show **dilated bowel loops, obstruction or abscesses**

Question 29

Describe the treatment regime for diverticulitis? [4]

Answer 29

mild cases of acute diverticulitis may be managed with **oral antibiotics, liquid diet and analgesia CKS** **dicycloverine**: antispasmodic if the symptoms don't settle within 72 hours, or the patient initially presents with more severe symptoms, the patient should be **admitted to hospital for IV antibiotics** **Consider open or laparoscopic resection** for patients who have recovered from complicated acute diverticulitis but have **continuing symptoms** (such as stricture or fistula)

Question 30

An anal longintudinal tear and fresh rectal bleeding is the diagnosis of? [1]

Answer 30

Anal fissure

Question 31

What are the three type of colon cancer? [3]

Answer 31

Sporadic (95%) Hereditary non-polyposis colorectal carcinoma (5%) Familial adenomatous polyposis (<1%)

Question 32

Describe the genetic influence of developing colorectal cancer [2]

Answer 32

**Hereditary non-polyposis colorectal carcinoma (aka Lynch syndrome; HNPCC, 5%):** - Autosomal dominant - DNA mismatch repair, effecting MSH2, MLH1, MHSH6, PMS2 genes - Does not cause adenomas - Tumours develop in isolation **Familiar adenomatous polyposis (FAP):** - autosomal dominant - malfunction of tumour suppressor gene adenomatous polyposis coli (APC) - causes many polyps in the large intestine

Question 33

What is the name for the staging criteria of colorectal cancer? [1] Describe each stage [4]

Answer 33

**Duke's classification**

Question 34

Describe how colorectal tumours can present via colonoscopy [3]

Answer 34

Ulcerating Stenosing Polypoidal

Question 35

What does this colonoscopy of colorectal cancer depict? Ulcerating Stenosing Polypoidal

Answer 35

Ulcerating Stenosing **Polypoidal**

Question 36

What does this colonoscopy of colorectal cancer depict? Ulcerating Stenosing Polypoidal

Answer 36

What does this colonoscopy of colorectal cancer depict? Ulcerating **Stenosing** Polypoidal

Question 37

What does this colonoscopy of colorectal cancer depict? Ulcerating Stenosing Polypoidal

Answer 37

What does this colonoscopy of colorectal cancer depict? **Ulcerating** Stenosing Polypoidal

Question 38

Options for managing bowel cancer (in any combination) are? [4]

Answer 38

**Surgical resection** Chemotherapy Radiotherapy Palliative care

Question 39

make sure you know about blood supply for colon bits (its different)

Question 40

All patients with newly diagnosed colorectal cancer should have which tests for staging? [3]

Answer 40

Entire colon evaluated with colonscopy or CT colonography Carcinoembryonic antigen (CEA) CT of the chest, abdomen and pelvis

Question 41

Describe the adjuvant chemotherapy given for colorectal cancer: [2] Describe the biologicals used [3]

Answer 41

Dukes B if poor prognositic factors Dukes C: - **Fluorouracil (5-FU)** - **Capecitabine** (first line) Biologicals: - **Cetuximab** (anti-EGFR) - **Panitumubab** (anti-EGFR) - **Bevacizumab** (anti-VEGF)

Question 42

Radiotherapy is used for pre-op. treatment of which specific type of colorectal cancer? [1]

Answer 42

**Rectal cancer**

Question 43

State 4 reasons why get referred to the two week cancer pathway for colorectal cancers [5]

Answer 43

**Positive FIT test** Over 40 years with abdominal pain and unexplained weight loss Over 50 years with unexplained rectal bleeding Over 60 years with a change in bowel habit or iron deficiency anaemia Any age with rectal or abdominal mass

Question 44

What type of treatment is radiotherapy generally used for in colorectal cancer? [2]

Answer 44

Palliative care Rectal cancers with high risk of local reoccurence

Question 45

Under which conditions do you only perform abdominal-perineal excision of rectum?[1]

Answer 45

Abdominal-perineal excision of rectum is only used when the anus is involved.

Question 46

What is the FOLFOX regime of treating colorectal cancer? [3]

Answer 46

Chemotherapy regime of: * 5-FU * Folinic acid * Oxaliplatin

Question 47

Which of the following involves removing the sigmoid colon and upper rectum but sparing the lower rectum and anus? Hartmann's procedure High anterior resection Left hemicolectomy Low anterior resection Right hemicolectomy

Answer 47

Which of the following involves removing the sigmoid colon and upper rectum but sparing the lower rectum and anus? Hartmann's procedure High anterior resection Left hemicolectomy **Low anterior resection** Right hemicolectomy

Question 48

What investigational method is used to properly ID a haemorrhoid? [1]

Answer 48

**Proctoscopy**

Question 49

Describe the topical treatments used for haemorrhoids? [3]

Answer 49

**Anusol**: - Chemicals used to shrink **Anusol HC** - As above but with hydrocortisone **Germoloids**: - Lidocaine

Question 50

Describe the non-surgical treatments used for haemorrhoids? [4]

Answer 50

**Rubber band ligation** Injection sclerotherapy IR coagulation Bipolar diathermy ## Footnote PassMed: outpatient treatments: rubber band ligation is superior to injection sclerotherapy

Question 51

What are the surgical treatment options for haemorrhoids? [4]

Answer 51

**Surgical haemorrhoidectomy** Haemorrhoid artery ligation Staple haemorrhoidectomy

Question 53

23. A 45-year-old man presents with a carcinoma 10cm from the anal verge, he has completed a long course of chemoradiotherapy and has achieved downstaging with no evidence of threatened circumferential margin on MRI scanning. What is the most appropriate colonic resction for this patient?

Answer 53

**Anterior resection with covering loop ileostomy** - 'carcinoma 10cm from the anal verge' implies that the anus is unaffected by the cancer. **Abdominal-perineal excision of rectum is only used when the anus is involved.** Low rectal cancer is usually treated with a low anterior resection. Contraindications to this include involvement of the sphincters (unlikely here) and poor sphincter function that would lead to unsatisfactory function post resection. Most colorectal surgeons defunction resections below the peritoneal reflection as they have an intrinsically high risk of anastomotic leak. A loop ileostomy provides a safe an satisfactory method of defunctioning these patients. A contrast enema should be performed prior to stoma reversal.

Question 54

After testing, he is found to be a carrier of the MSH2 gene and is subsequently diagnosed with HNPCC. Aside from colorectal cancer, which of the following is the patient at greatest risk of developing? Endometrial cancer Lung cancer Medulloblastoma Pancreatic cancer Thyroid cancer

Answer 54

After testing, he is found to be a carrier of the MSH2 gene and is subsequently diagnosed with HNPCC. Aside from colorectal cancer, which of the following is the patient at greatest risk of developing? Endometrial cancer Lung cancer Medulloblastoma **Pancreatic cancer** Thyroid cancer HNPCC is associated with an increased risk of endometrial cancer, however this patient is male.