AnoRectal Disorders

Question 1

Describe the nerve supply of the pelvic region?

Specifically the pelvic organs, pelvic floor muscles, puborectalis and external sphincter nerve supply.

Answer 1

• Pelvic Organs are supplied by the sympathetic fibres of L1-L2 and parasympathetic fibres of S2-S4. (Lumbar and pelvic splanchnic nerves)
• Pelvic floor uscles are supplied directly by ventral rami of sacral spinal nerves S2-4
• Puborectalis and external sphincter are supplied by the ventral rami of s2-4 spinal nerves via the pudendal nerve.`

Question 2

What are the categories of anorectal disorders?

Answer 2

Inflammatory
Infection
Malignancy
Trauma
Congenital

Question 3

List some congenital anorectal abnormalities?

Answer 3

• Imperforate Anus
• Uro-genital Fistulae
• Hirschprung’s Myenteric plexus deficiency

Question 4

What are the types of imperforate anus?

Answer 4

• Pouch shaped rectum fails to connect with colon
• Anus stenosed or absent
• Rectum opening to other structures e.g. urethra

Question 5

What is hirschprung’s myenteric plexus deficiency?

Answer 5

The nerves suppling the end of the colon are missing leading to an inability to shit.
The baby fails to defecate in the first 48 hours of life and vomits bile

Question 6

How do we treat hirschprungs myenteric plexus deficiency?

Answer 6

Pre-op:
IV nutrition, bowel washouts and antibiotics if necessary

Surgery:
Remove uninnervated bowel section and attach an innervated section to the rectum

Question 7

List of the acquired anorectal conditions:

Answer 7

• Haemorrhoids
• Anal fissure
• Abscess
• Fistula in-ano
• Ulceration
• Cancer
• Continence control

Question 8

What is a haemorrhoid?

Answer 8

An inflamed and swollen vein in the anal canal causing enlarged anal cushions.

Associated with straining, constipation etc.

Question 9

How does a haemorrhoid present?

Answer 9

• Itching
• Irritation/pain
• Lumps/swelling
• Faecal Leakage
• painful bowel movements
• haematochezia

Theres no pain if the haemorrhoid is above the dentate line

Question 10

What is the dentate line?

Answer 10

A line which divides the upper two thirds and lower third of the anal canal.
This line represents the divide of feeling

Question 11

How do we treat a haemorrhoid?

Answer 11

With

• pain relief
• Fibre supplements
• Ligation either by rubber banding the haemorrhoid or US guided ligation of the vessel
• Stapled anopexy

Question 12

Explain the stapled anopexy procedure?

Answer 12

For haemorrhoids and prolapse.

Use a special device to cut out a doughnut shape of mucosa and stable the tissue above and below together

Question 13

What causes an anal fissure and how does it present?

Answer 13

• Straining e.g. constipation
• Persistant diarrhoea
• IBD
• Pregnancy & Childbirth

Presents with sharp pain when passing stool and haematochezia. Followed by persistant burning pain,

Question 14

How do we treat an anal fissure?

Answer 14

Most resolve independantly
Fibre & Hydration
Pain relief
~laxatives

Question 15

What causes anal abcess in the ano-rectal region and how do they present?

Answer 15

Usually blocked small anal glands becomes infected, STI or an infected fissure.

A perianal abscess is most common, appearing like a painful boil like swelling near the anus, red an warm.
Also with constant, throbbing pain worse when seated, skin irritation, pus and constipation/pain with bowel movements.

Question 16

How is an anal abscess complicated/treated?

Answer 16

Fistula formation

Treated with surgical incision and drainage followed by pain relief and antibiotics as necessary

Question 17

What is an anal fistula and how does it arise?

Answer 17

A narrow channel connecting anal canal externally to the skin near the anus.
Usually results from an abscess but also from IBD or diverticulitis

Question 18

How does an anal fistula present?

Answer 18

• Skin irritation
• Pain. Constant, throbbing, worse when seated moving shitting or coughing
• Smelly discharge
• Pus in stool
• haematochezia
• Incontinence
• Swelling/redness

Question 19

How do we treat an anal fistula?

Answer 19

Fistulotomy:

• Cut open length of fistula
• Heals to a flat scar
• For superficial fistulas

Seton Suture:

• Suture loops through fistula to keep it open so the pus drains until it heals
• For trans-sphincteric fistulas (starts between the sphincters and crosses the external on its way out)

Glue Plug:

• Clean out fistula and drain pus
• Block fistula with glue and cover with a flap of tissue

Question 20

What could cause ulceration of the anorectal region?

Answer 20

• IBD, mostly crohn’s
• Malignancy
• Syphilis
• Nicorandil (angina vasodilator)

Question 21

How does a cancer in the anorectal region present and how would we investigate it?

Answer 21

Rectal bleeds, itching and pain, small lumps, bowel incontinence, mucous from anus.

• Rectal exam
• Colonoscopy
• CT Colonography
• MRI guided colonoscopy

Question 22

How do we classify colonic and anorectal cancer?

Answer 22

Dukes classification
A - Submucosa
B - Muscle wall
C - Lymph nodes
D - Metastases

Question 23

Hwo do we treat anorectal cancer?

Answer 23

If its squamous cell carcinoma use radiotherapy

If its rectal adenocarcinoma neoadjuvant chemo and a laprascopic resection

Question 24

What are the 2 types of incontinence?

Answer 24

Urge bowel - sudden need to go and not enough time

Passive - No sensation prior to soiling themselves

Question 25

What causes incontinence?

Answer 25

• Rectal problems such as constipation - fistula-in-ano - bowel impaction (weakens rectal wall muscles) - rectal prolapse -
  Diarrhoea - Scarring of the rectum - Haemorrhoids
• Problems with the sphincter muscles due to trauma, childbirth, surgery or congenital disorders (e.g. hirschprungs)
• Nerve damage to the hypogastric plexus (upper 1/2 of anal canal) or inferior rectal nerves (lower 1/2)
  OFten caused by diabetes, MS, stroke or spina bifida