Lower Gi Things

Front 1

What is fissure in ano?

Back 1

Longitudinal split in the anoderm of the distal anal canal, which extends from the anal verge proximally towards dentate line BUT not beyond it.

Front 2

Difference between posterior and anterior anal fissure

Back 2

Posterior

Commonly seen in most anal fissure cases

Anterior

Commonly in females after vaginal delivery

Front 3

Difference between acute and chronic fissure in ano

Back 3

Acute

Tear on the anal mucosa

Chronic

Acute fissure persist more than 6 weeks

Front 4

Causes of fissure in ano

Back 4

1. Constipation -Traumatisation of the anal mucosa by passage of hard stool

2. Chronic diarrhea (less commonly)

3. Vaginal delivery (anterior anal fissure)

4. STI / HIV / TB

5. IBD / Cancer

6. Pregnancy

7. Prior anal surgery

8. Anal sexual intercourse

Front 5

Risk factors fissure in ano

Back 5

1. Trauma (hard bowel movements, diarrhea, anal instrumentation, child birth)

2. Low fibre intake

3. Physiological stress (sustained tonic rise anal canal pressure)

4. Inflammatory bowel disease (Crohn’s D)

Front 6

Common complaint fissure in ano

Back 6

1. Severe pain during defecation (feel like broken glass passed through anal)

2. Passage of fresh blood

3. Itchiness (in chronic)

Front 7

What can be seen during inspection of fissure in ano

Back 7

1. Hypertrophied anal papilla internally (chronic anal fissure)

2. Sentinel tag externally (chronic anal fissure)

3. Demarcated, fresh mucosal edges and granulation tissue (at the base of the fissure)

Front 8

What is the classic triad of chronic fissures

Back 8

1. Deep ulcer

2. Sentinel pile at the distal fissure margin

3. Enlarged anal papillae proximal to fissure

Front 9

What investigations done for fissure in ano?

Back 9

1. Examination under anaesthesia (particularly to exclude presence of occult perianal abscess or tumour in older patients) -secondary causes of anal ulceration.

2. Flexible sigmoidoscopy- determine cause of fissure (<50 y/o with no risk factors for intestinal disease or colon ca)

3. Colonoscopy- for pt >50y/o with abdominal sx like diarrhea.

Front 10

What is the treatment for acute anal fissure

Back 10

*main aim of the tx is to breaking the cycle of hard stool, pain and internal anal sphincter spasm*

1. Dietary modification- high fibre diet + increase water intake

2. Laxatives- syrup lactulose/liquid paraffin

3. Warm sitz baths- relieve symptoms

4. Avoidance of topical preparations of hydrocortisone and local anesthetics

Front 11

What is the tx of chronic anal fissures

Back 11

*main aim of tx is to reduce internal sphincter spasm and anal canal pressure*

1. Pharmacologic agents- topical nitroglycerin, CCB (nifedipine, diltiazem), botulinum toxin -to lower resting anal pressure and promote fissure healing

2. Surgery- Lateral internal sphincterotomy, Lord’s anal stretch, fissurectomy, lateral anal sphincterotomy (Notaras) and advancement flap anoplasty (reserved for refractory anal fissures)

3. Oral analgesics- avoid use of codeine (adverse effect of constipation)

4. Other oral and topical agents- bethanecol, indoramin, albuterol, sildenafil (decrease resting pressure of anal sphincter BUT not promoting healing)

5. F/up to assess outcome of tx

Front 12

Mdm Choo, a 30y/o Chinese woman presented to your clinic with a hx of severe pain on defecation for the last 1 month. she has noticed a small amount of blood on the stool and also on the toilet paper after wiping. the pain is severe and she felt like a broken glass passed through her anus, and it often persists for hours after defecation.

State FIVE causes of anorectal pain.

Back 12

1. Acute anal fissure

2. Thrombosed hemorrhoids

3. Peri-anal ulcer (Crohn's D, extrapulmonary TB or syphilis)

4. Anal fistula (infected with abscess formation)

5. Solitary rectal ulcer syndrome

Front 13

Mdm Choo, a 30y/o Chinese woman presented to your clinic with a hx of severe pain on defecation for the last 1 month. she has noticed a small amount of blood on the stool and also on the toilet paper after wiping. the pain is severe and she felt like a broken glass passed through her anus, and it often persists for hours after defecation.

What further histories would you like to obtain from this pt?

Back 13

Ask hx of TB, Crohn D and use of opiate analgesia

- Extrapulmonary TB and Crohn D may be associated with anal fissures

- Use of opiate analgesia is associated with constipations and subsequent increased incidence of anal fissure

Front 14

What is fistula in ano

Back 14

Fistula in ano is refers to an abnormal communication (tract) between the anal canal or rectum (deeply) and the perianal skin (superficially).

Front 15

What are the four main types of anal fistula according to Park’s classification?

And which one is the most common?

Back 15

1. Inter-sphincteric (MOST COMMON)

2. Trans-sphincteric

3. Supra-sphincteric

4. Extra-sphincteric

Front 16

What is the classification for fistula in ano

Back 16

Park’s classification

- Based on the relationship of tract with the external anal sphincter

Front 17

Explain the types of fistula in ano

Back 17

1. Inter-sphincteric

- MOST COMMON

- Begins at dentate line and ends at anal verge, tracking along the intersphincteric plan between the internal and external anal sphincters and terminates in perianal skin

2. Trans-sphincteric

- Tracks through the external sphincter into the ischiorectal fossa, encompasses a portion of the internal and external sphincter and terminates in the skin overlying the buttock

3. Supra-sphincteric

- RARE (usually due to iatrogenic)

- Originates at the anal crypt and encircles the entire sphincter apparatus, terminates in the ischiorectal fossa

4. Extra-sphincteric

- Commonly due to pelvic trauma, very high in anal canal, located proximal to the dantate line. It encompasses the entire sphincter apparatus including levator and terminates in the skin overlying the buttock

Front 18

What are the complications of anorectal abscesses?

Back 18

1. Fistula formation

2. Bacteremia and sepsis

3. Fecal incontinence

4. Malignancy

Front 19

What are the factors that contributing to recurrence of the anorectal abscess?

Back 19

1. Inadequate drainage of the abscess

2. Presence of unrecognised anal fistula

3. TB

4. Actinomycosis

5. HIV or immunosuppression

Front 20

What fascia anteriorly separates the rectum from prostate and seminal vesicles in men and from the vagina in women?

Back 20

Denonvillier’s fascia

Front 21

What is used clinically to predict the trajectory of a fistula tract

Back 21

Goodsall’s rule

Front 22

What is the length of surgical anal canal?

Back 22

2 - 4cm

Begins at anorectal juction and terminates at the anal verge

Longer in men than women

Front 23

What is the dentate / pectinate line marks?

Back 23

The dentate / pectinate line marks the transition point between columnar rectal mucosa and squamous anoderm

Front 24

Causes of anorectal abscess

Back 24

1. Obstructed anal crypt originating at the dentate line

2. Extension of an infection of an anal gland

3. Hematogenous infections

4. Penetrating foreign bodies

5. Extension of cutaneous boil

Front 25

State level of fistula in ano

Back 25

Low level fistula (below ano-rectal ring)

- Submucous

- Inter muscular

- Anorectal

High level fistula (above ano-rectal ring)

- Total fistula secondary to local disease

- Total fistula with high perforating secondary tract

- High intersphincteric fistula starting as a primary anal gland

Front 26

Clinical presentation of pt with anorectal abscess

Back 26

1. Severe pain in the anal or rectal area

- Pain is constant (not necessarily a/w bowel movement) exacerbated when sat down

- Throbbing in nature

2. Localised swelling

3. Fever and malaise

4. Urinary retention (progressive infection)

5. Purulent rectal drainage

Front 27

Supralevator abscesses are typically a/w ?

Back 27

Pelvic pain and tenderness

Front 28

What positioning can be done to inspect pt with anorectal abscess?

Back 28

1. Left lateral position (Sim’s)

2. Knee-elbow position

3. Lithotomy position

Front 29

Where do the anorectal abscesses occur classically?

Which one is the commonest?

Back 29

1. Perianal (MOST COMMON)

2. Ischiorectal

3. Inter-sphincteric

4. Supralevator

5. Submucosal

Front 30

Mr X, 45 y/o gentleman presented to the outpatient clinic due to peri-rectal pain a/w mild fever, generalised malaise, loss of appetite and chills, for 4 days duration.

List FIVE differential diagnosis

Back 30

1. Anorectal abscess

2. Anal fissure

3. Thrombosed hemorrhoids

4. Pilonidal abscess

5. Perianal hidradenitis suppurativa

Front 31

What investigations can be done for anorectal abscess pt?

Back 31

1. FBC

2. Serum glucose - TRO DM (predisposed to abscess formation)

3. Renal profile - serum BUN and creatinine may be elevated, metabolic acidosis (decreased bicarbonate and increased base deficit) common in pt with necrotising soft tissue infections

4. Pus culture and sensitivity for antibiotic

5. CT or MRI - for nonpalpable anorectal abscess, complicated, unclear, or chronic disease (immunocompromised or those with ischiorectal abscesses)

6. Anoscopy (after pain subsides)- to determine whether anal fistula has developed as sequelae of abscess

Front 32

What is the outline of management of anorectal abscess?

Back 32

1. Antibiotic therapy, as guided by protocol

2. Sufficient analgesia

3. The main management for anorectal abscesses- incision and drainage procedure (always be performed under general anaesthetic) These can left to heal by secondary intention.

4. Once drained, proctoscopy should be performed (presence of any identifiable fistula-in-ano)

Front 33

What is the classification for fistula in ano

Back 33

Park’s classification

- Based on the relationship of track with the external anal sphincter

Front 34

Explain the types of fistula in ano

Back 34

1. Inter-sphincteric

- MOST COMMON

- Begins at dentate line and ends at anal verge, tracking along the intersphincteric plan between the internal and external anal sphincters and terminates in perianal skin

2. Trans-sphincteric

- Tracks through the external sphincter into the ischiorectal fossa, encompasses a portion of the internal and external sphincter and terminates in the skin overlying the buttock

3. Supra-sphincteric

- RARE (usually due to iatrogenic)

- Originates at the anal crypt and encircles the entire sphincter apparatus, terminates in the ischiorectal fossa

4. Extra-sphincteric

- Commonly due to pelvic trauma, very high in anal canal, located proximal to the dantate line. It encompasses the entire sphincter apparatus including levator and terminates in the skin overlying the buttock

Front 35

Causes of fistula in ano

Back 35

1. Consequence of an perianal or submucous abscess bursting both outside and inside

2. Inadequate drainage of an ano-rectal abscess

3. Other associated risks factors

Front 36

Risk factors for the formation of fistula in ano

Back 36

1. IBD – Crohn’s disease or ulcerative colitis

2. Systemic diseases – Tuberculosis, diabetes, HIV

3. History of trauma to the anal region

4. Previous radiation therapy to the anal region

Front 37

Clinical presentation of pt with fistula in ano

Back 37

1. Presented with non-healing/ persistent anorectal abscess following drainage, or with chronic purulent drainage and a pustule-like lesion in the perianal or buttock area

2. Intermittent rectal pain (during defecation, also with sitting and activity)

3. Intermittent and malodorous perianal drainage

4. Pruritus

5. On PE, an external opening on the perineum may be seen (these can be fully open or covered in granulation tissue)

6. A fibrous tract may be felt underneath the skin on digital rectal examination.

Front 38

What is used clinically to predict the trajectory of a fistula tract

Back 38

Goodsall’s rule

Front 39

What investigations can be done in pt with fistula in ano

Back 39

1. Proctoscopy - May demonstrate inner opening of the fistula

2. Probing and sinogram -EUA (demonstrate tract of the fistula)

3. MRI - Gold standard for fistula imaging (reserved for difficult recurrent cases or view secondary extension that may be missed during surgery)

4. Fistulography and CT - useful for extra-sphincteric fistula

5. Barium enema - useful for pt with multiple fistula or recurrent disease TRO IBD

Front 40

What are the tx options for fistula in ano?

Back 40

1. Therapeutic intervention is indicated for symptomatic

2. Surgical tx is the mainstay of therapy

*injection of hydrogen peroxide to detect internal opening of anal fistula*

3. Surgical options:

- Fistulotomy

- Ligation of the inter-sphincteric fistula tract (LIFT)

- Mucosal advancement flap

4. Others:

- Seton placement (single stage and two stage)

- Fibrin glue

- Bioprosthetic plug