Colorectal

Question 1

How are anal fissures treated?

Answer 1

Anal fissure is a longitudinal tear in the mucosa of the anal canal, often caused by a large, difficult to pass stool.
Can be treated conservatively or surgically.
Conservative -> stool softeners/laxatives to prevent hard stools, topical GTN, botulinium toxin injection, diltiazem ointment (Ca channel blocker)
Surgical -> lateral submucous sphincterotomy (internal sphincter)

Question 2

What is an anal fissure?
How does if develop?
What causes it to persist?

Answer 2

Anal fissure is a longitudinal tear of the anal mucosa. Distal to the dentate line.
Primary fissures develops commonly from hard, impacted faeces and commonly occur posterior or anteriorly. Secondary fissures occur from conditions such as IBD, or malignancy and commonly occur laterally.
Microtrauma to the area causes local vasoconstriction and release of inflammatory mediators, reducing local blood supply and reducing the opportunity for repair

Question 3

How would you go about investigating a previously well 63 year-old man who presented to you with a short history of rectal bleeding?

Answer 3

History -> duration, quantity, PMH, FHx, Sx
Examination -> PR, Abdo exam
Investigation -> FBC, CT abdo

Question 4

How would you go about investigating a previously well 63 year-old man who presented to you with a short history of anaemia?

Answer 4

History -> duration, severity, pain, blood loss, diet, PMH, FHx, Sx
Examination -> Abdo exam, cardio exam
Investigation -> CT abdo, ECG, FBC

Question 5

How would you go about investigating a previously well 63 year-old man who presented to you with a short history of a change in bowel habit to more frequent evacuation of loose stools with mucus?

Answer 5

Most likely diagnosis is a villous adenoma. Ddx include UC, Campylobacter, C. Difficile
History -> duration, pain, mucous, fever, PMH, FHx, Sx
Examination -> abdo exam
Investigation -> FBC/UEC, stool MCS, CT abdo

Question 6

What are the major risk factors for colorectal cancer?

Answer 6

non modifiable -> age, FHx, male, IBD, FAP

modifiable -> smoking, sedentary lifestyle, diet

Question 7

What method is used for population screening for colorectal cancer in Australia?

Answer 7

Colorectal cancer is the second most common cancer in Australia. FOBT is recommended.
Low risk -> commences in 50+ for asymptomatic with no FHx for every 2 years until 74
Med risk -> People with 1 FHx of CRC <55, or 2+ at any age: FOBT from 40 every 2 years, colonoscopy every 5 years from 50
High risk -> people with >3 FHx of CRC: FOBT every 2 years from 35, colonoscopy every 5 years from 45, referral for genetic screening

Question 8

What is neoadjuvant therapy for rectal cancer?

Answer 8

Neoadjuvant therapy given pre-operatively. Indicated for T3/4 tumours, clinically node positive T1/2 tumours, distal rectal tumours requiring an abdomino-pelvic resection.
Treatment is with fluorupyrimidine based chemotherapy or radiation therapy.

Question 9

Where are the common sites that metastatic disease from a colorectal primary are found?

Answer 9

Liver, lungs, brain, bone, skin, adrenals.

Transmitted through lymphatic spread

Question 10

What are the treatment options for liver metastases from a colorectal primary?

Answer 10

In advanced disease, survival is poor with most only living up to 2 years. The exception is liver mets, with prolonged survival in up to 40%.
Surgical resection: removal of hepatic mets, ensure no extrahepatic mets, contraindicated in patients with >70% liver involvement, or involvement of the CBD, hepatic artery or portal vein.
Non-surgical management: radiotherapy (endovascular therapy through hepatic artery), chemotherapy

Question 11

What is the adenoma-carcinoma sequence?

Answer 11

The stepwise mutational pattern of increased proto-oncogene expression and decreased tumour suppressor gene expression by cancer develops. It is the process in which epithelial cells acquire severe genetic mutations.
Takes 5-10 years to develop. This sequence accounts for 80% of sporadic colon tumours and typically involves mutation of the APC early in the process. 1% of tumours >1cm are adenocarcinoma, 10% >2cm

Question 12

What is Crohn’s disease?

Answer 12

Crohn’s disease is a chronic relapsing inflammatory bowel disease that can affect anywhere along the gastrointestinal tract. It is most commonly associated with younger people. Often involves more than 1 part of the bowel, with spared areas inbetween (skip lesions). Inflammation of the bowel is through the entire wall (transmural), with affected areas potentially obstruction, fistulating or perforating. The wall becomes thickened with oedema. Epithelium is usually intact, but criss-crossed with large ulcers
Aetiology is unknown, but there are risk factors of FHx, smoking, OC and ethnicity.
Presents as cramping abdominal pain, weight loss, non-bloody diarrhoea and general malaise.
Medical management is most appropriate

Question 13

What is diverticular disease?

Answer 13

Diverticular disease encompasses the symptoms and signs associated with the presence of diverticular. Diverticular are outpouchings of the bowel wall.
Occurs in 10% of people over the 45, and 65% of people 70+. Affects men and women equally and occurs mostly in the sigmoid colon. Diverticulitis is symptomatic diverticula, that occur when the neck is obstructed by things such as faeces. Can result in the formation of a diverticula abscess.
chronic presentation -> abdominal pain and erratic bowel habits
acute presentation -> LIF pain, peritonism, systemic illness, fever

Question 14

What are the major complications that can result from diverticulitis?

Answer 14

Diverticulitis is symptomatic diverticula disease, commonly caused when the diverticula neck is obstructed by an object such as faeces resulting in an inflammatory process. Major complications include:
abscess, diverticula perforation, fistula formation, pneumaturia, bowel obstruction

Question 15

What are haemorrhoids and how are they classified or described?

Answer 15

Haemorrhoids are engorged vascular structures that form in the submucosa layer of the anal canal.
Constipation and pregnancy are the most common cause of haemorrhoids (increased IAP). Increased pressure exacerbated by straining causes venous pooling, and engorgement of the venous plexus. Bulging mucosa then dragged down by stool. Most often located at 3, 7 and 11 o’clock (supine lithotomy position) correlating to the anatomical anal cushions. Can be classified into 4:
1 -> never prolapse
2 -> prolapse, return spontaneously
3 -> prolapse, do not return spontaneously
4 -> prolapse, do not return

Question 16

How are symptomatic haemorrhoids treated?

Answer 16

Depends on the classification. Can be treated conservatively or surgically.
Conservative treatment includes avoiding bulky stool with stool softeners, high fibre, avoiding straining.
Surgical treatment includes:
1. Sclerotherapy (2nd) -> sclerosing agent applied to vessels that supply the haemorrhoid
2. Banding (2nd) -> cone band placed around stalk of the haemorrhoid to stop blood supply. Not placed around stalks of prolapsing haemorrhoid
3. Haemorrhoidectomy -> surgically removed. Used in 3rd degree or higher. Must maintain a mucosal gap between lesions
4. HALO -> arterial supply found with USS and stitch is placed around

Question 17

What are the indications for elective surgery in a patient with ulcerative colitis?

Answer 17

Ulcerative colitis is a chronic inflammatory condition of the bowel. Surgical intervention is appropriate with failure of medical management (corticosteroids), or symptoms that are too severe for the patient. Surgery can be considered curative.
Only ~20% require surgery. Other reasons for surgery include medication intolerance/allergy, risk of malignancy, failure to thrive, symptoms of disease. Complications requiring surgery include perforation, fistulation, haemorrhage, toxic megacolon.

Question 18

What are the indications for elective surgery in a patient with Crohns?

Answer 18

Crohn’s disease is a chronic relapsing inflammatory condition that can affect anywhere along the GIT. Presence of skip lesions is characteristic. Mostly treated medically, with the use of anti-inflammatories or immune-modulators. Surgery should not be considered curative. but is necessary in up to 70% of patients due to failure of medical management, severe symptoms, failure to thrive, complications.

Question 19

What are the indications for emergency surgery in a patient with inflammatory bowel disease?

Answer 19

Ulcerative colitis or Crohn’s disease. Indications include:
Toxic megacolon, perforation, fistulation, haemorrhage, obstruction, symptomatic intra-abdominal abscess, deterioration on maximum medical treatment.

Question 20

You are the ED intern on duty. You are asked to see a 20 year-old man who has presented with perianal pain that started 24 hours ago and has got worse despite appropriate analgesia. The pain is worse when he walks or sits. This has not happened before. He has no other relevant history. On examination you find a fluctuant, warm, red 3cmx3cm swelling at the anal margin. What is the likely diagnosis?

Answer 20

Most likely to be a perianal abscess.
Abscess with the anal region is a common surgical emergency. It is initially due to purulent infection of the anal glands which lie in the intersphincteric space.
Risk factors of smoking, men, age, IBD
Treatment includes surgical incision and drainage. Must assess the extent of the abscess before drainage. Depending on size may require packing. Addition of Abx does not help

Question 21

You are the ED intern on duty. You are asked to see a 20 year-old man who has presented with perianal pain that started 24 hours ago and has got worse despite appropriate analgesia. The pain is worse when he walks or sits. This has not happened before. He has no other relevant history. On examination you find a fluctuant, warm, red 3cmx3cm swelling at the anal margin. What is the likely diagnosis?
What aetiological factors are associated with this condition?

Answer 21

The likely diagnosis is a perianal abscess.
Arises from inflammation of the anal glands which drain into the anal crypts. Blockage occurs with stool impaction, oedema or other adjacent inflammatory processes.
2x in men, median age of 40, smokers, IBD

Question 22

What is ulcerative colitis?

Answer 22

Ulcerative colitis is a chronic inflammatory condition that affects the large bowel. Causes ulceration and inflammation of the mucosa and submucosa. It is characterised by acute exacerbations of a chronic disease. Always involves the rectum and moves proximally from there.
On histology there is signs of inflammation, crypt abscesses and neutrophilia.
Systemic features of anaemia, lethargy and associated autoimmune conditions of inflammatory arthritis, psoriasis. Stool is bloody, mucous and loose. Complications include toxic megacolon (dilated and necrotic bowel), perforation, fistulation

Question 23

This lesion is found at colonoscopy in the proximal colon. What is it?
How should it be treated?
Is follow up or surveillance needed?

Answer 23

This is most likely to be a polyp (localised lesion protruding from the bowel). Polyps can be pedunculated, adenomatous or sessile. Adenomatous are the most common. Due to the adenoma-carcinoma sequence the polyp should be removed. Adenomas can be classified as:
1. villous -> finger like projections
2. tubular -> cells tubular like (most common)
3. tubulovillous -> properties of both
Villous growth patters have the largest chance of developing into cancer.
Follow up is required with repeat colonoscopies.
1. 5 years -> 1-2 adenomas <10mm, no villous or high grade dysplasia
2. 3 years -> 3-4 adenomas or >10mm, villous, high grade dysplasia
3. 1 year -> 5+ adenomas

Question 24

This 22 year-old female patient presents with vague intermittent right sided abdominal discomfort and some mild diarrhoea. What abnormality is evident here in the terminal Ileum and right colon at colonoscopy?
What histopathological findings are anticipated in the biopsy findings of this lesion?
What are possible diagnoses?

Answer 24

Crohn’s disease.
Expect inflammatory changes, widening of submucosa, neutrophilia, cryptitis with abscesses forming.
strictures, ulceration, discontinuous lesions
Other possible diagnosis include: infectious colitis, ulcerative colitis

Question 25

This lesion is found at colonoscopy in the sigmoid colon of an 85 year-old male admitted acutely with a near complete large bowel obstruction. What is the lesion?
What initial treatment is most appropriate for this patient whose CT scan shows a large number of bilobar hepatic metastases?
What are the major risks of this approach?

Answer 25

The lesion is a carcinoma of the bowel.
Initial treatment can be curative or palliative -> also needs analgesia/anti-emetic. Palliative approach would include stenting, or surgical removal to clear the lumen. Treatment would include neoadjuvant therapy of chemotherapy or radiation, removal of hepatic mets if <70% involvement + no involvement of CBD, hepatic artery or portal vein and surgical removal of primary lesion with a bowel resection.
Major risks of surgery + risk of recurrence. Risk of stenting is perforation, failure, haemorrhage, tenesmus

Question 26

What is the obvious abnormality on this X-ray and in this operative photo?
In the presence of symptoms of large bowel obstruction what initial treatment options exist?
What can be done to prevent recurrence?

Answer 26

Sigmoid volvulus. Symptoms of LBO include bloating, pain, nausea, constipation, dehydration. Initial treatment involves analgesic.
Advance flexible sigmoidoscope up the rectum and pass flatus tube through the area of volvulus
To prevent recurrence, stay hydrated, diet high in fibre or a surgical sigmoid colectomy

Question 27

This is a photo of a patient with a loop defunctioning colostomy. What is the abnormality seen here?
What is the mechanism?
What treatment options are there?

Answer 27

Parastomal hernia
Mechanism is a weakening of the abdominal musculature formed through the creation of the stoma. Bowel contents protrude through this gap. management includes patient education with supportive care, replacement of the stoma, mesh repair of the hernia.

Question 28

What is the lesion visible here at colonoscopy and what has been done?
What is the possible histology?
What additional endoscopic manoeuvre is needed before completion of the colonoscopy?

Answer 28

There is a polyp visible and they are performing a snare excision. Possible histology is villous, tubular, or tubulovillous
Additional manoeuvre is retrieval of the polyp and retroflexion of the scope

Question 29

This patient presents with anal discharge and pain. What is What is the likely nature of this lesion?
What does the initial management involve?
How is it usually treated?
What is the role of surgery?

Answer 29

Anal cancer. (SCC)
initial management is history, examination and investigation with a biopsy of the lesion.
Treatment is with neoadjuvant therapy of chemo/radiotherapy
Surgery is indicated to reduce the chance of recurrence or for tumours that do not respond appropriately to neo-adjuvant therapy

Question 30

This patient presented with severe anal pain after lifting a heavy piece of furniture. He feels this perianal swelling but does not present to his GP for a couple of days. What is the diagnosis?
What is the treatment?

Answer 30

Diagnosis is thrombosed external haemorrhoids or strangulated internal haemorrhoids. May have thrombosed due to the increased pressure when lifting
Analgesia for the patient and an excisions (haemorrhoidectomy) is the most likely management. May also opt for banding. As it is external there is cutaneous innervation

Question 31

This man had had an abscess drained in the perianal region.
Q1: What is the common presentation of this problem?
Q2: What is the first line of management?
Q3: What bacteria are usually cultured?
Q4: What is the usual cause of this?

Answer 31

Perianal abscess presents as a painful lump that hurts particularly when walking/sitting that is not relieved by analgesia
First line management is a surgical incision and drainage. Abx can be given
Bacteria most likely to be cultured include E. Coli, staph aureus.
perianal abscess is caused by blockage of the anal ducts which drain from the anal crypts. Commonly from impacted faeces, IBD, trauma. Abscess can spread upwards (ischiorectal abscess), laterally (intersphincteric abscess) or downwards (perianal abscess).

Question 32

This is a photo of the anal canal taken at colonoscopy by retroflexion of the scope.
Q1. What does this show?
Q2. How do these present clinically?
Q3. How are they treated?

Answer 32

The photos shows the presence of internal haemorrhoids (bulging venous cushions).
Present clinically as bleeding, itch, pain on defecation, thrombosed, prolapse
Treatment depends on grading:
1-3 -> conservative treatment with diet, stool softeners, no straining
surgical options of banding, sclerotherapy, HALO
4 -> haemorrhoidectomy

Question 33

This patient presents with perianal itching.
Q1. What are the lesions you can see in the perianal area?
Q2. What is the responsible agent that causes this condition?
Q3. What treatments are available?

Answer 33

Lesions are likely to be anal warts. The agent that causes this is HPV. Strains 6 and 11 are most common. Transmitted sexually. Can increase the risk of perianal cancer (like HPV in cervical cancer)
Treatments available include topical imiquimod (cytokine stimulator), TCA, cryotherapy, surgical excision