Anal fistula: Difference between revisions

 
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==Background==
==Background==
*Inflammatory tract originating from infected anal gland connecting anal canal w/ skin
[[File:Rectum anatomy en.png|thumb|Anatomy of the anus and rectum.]]
[[File:Fistula diag 01.png|thumb|Different types of anal fistulas.]]
*Inflammatory tract originating from infected anal gland connecting anal canal with skin
**May be intersphincteric, suprasphincteric, transsphincteric, or extrasphincteric
**May be intersphincteric, suprasphincteric, transsphincteric, or extrasphincteric
*Goodsall's Rule
*Goodsall's Rule
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***If external opening is anterior to this line fistula runs directly into the canal
***If external opening is anterior to this line fistula runs directly into the canal
***If external opening is posterior to this line fistula curves to post midline of canal
***If external opening is posterior to this line fistula curves to post midline of canal
*Causes:
 
**Perianal/ischiorectal abscess, Crohn, UC, malignancies, STI, fissures, FBs, TB
===Causes===
*[[perianal Abscess|Perianal]]/ischiorectal abscess
*[[Crohn's]]
*[[Ulcerative colitis]]
*Malignancy
*[[STI]]
*[[Anal fissure]]
*[[Rectal foreign body|foreign bodies]]
*[[TB]]
 
==Clinical Features==
==Clinical Features==
*Fistulous tract open: Persistent, painless, blood-stained, mucous, malodorous discharge
*Fistulous tract open: Persistent, painless, blood-stained, mucous, malodorous discharge
*Fistulous tract blocked: Bouts of inflammation that are relieved by spontaneous rupture
*Fistulous tract blocked: Bouts of inflammation that are relieved by spontaneous rupture
*Abscess
*[[perianal Abscess|Abscess]]
**Throbbing pain that is constant and worse w/ sitting, moving, defecation
**Throbbing pain that is constant and worse with sitting, moving, defecation
**May be only sign of fistula
**May be only sign of fistula
*Fistulous opening
*Fistulous opening
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{{Anorectal DDX}}
{{Anorectal DDX}}


==Diagnosis==
==Evaluation==
*Endocavitary US w/ 3% hydrogen peroxide for definitive diagnosis
*Endocavitary [[ultrasound]] with 3% hydrogen peroxide for definitive diagnosis
==Management==
==Management==
#Ill-appearing
#Ill-appearing
##Analgesia
##[[Analgesia]]
##IVF
##[[IVF]]
##Anbx
##[[Antibiotics]]
##Urgent surgical consultation
##Urgent surgical consultation
#Well-appearing
#Well-appearing
##Abx
##Antibiotics
###Ciprofloxacin 750mg PO BID AND metronidazole 500mg QID x7d
###[[Ciprofloxacin]] 750mg PO BID AND [[metronidazole]] 500mg QID x7d
##Outpt sx referral
##Outpatient surgery referral
###Improperly excised fistulas may result in permanent fecal incontinence
###Improperly excised fistulas may result in permanent fecal incontinence
##Spasm treatment
##Spasm treatment
###Nitroglycerin, Lidocaine
###[[Nitroglycerin]], [[Lidocaine]]
###Sitz baths
###Sitz baths


==See Also==
==See Also==
[[Anorectal Disorders]]
*[[Anorectal Disorders]]
 
==References==
<references/>


==Source==
Tintinalli


[[Category:GI]]
[[Category:GI]]
[[Category:Surgery]]

Latest revision as of 21:50, 7 July 2021

Background

Anatomy of the anus and rectum.
Different types of anal fistulas.
  • Inflammatory tract originating from infected anal gland connecting anal canal with skin
    • May be intersphincteric, suprasphincteric, transsphincteric, or extrasphincteric
  • Goodsall's Rule
    • Draw imaginary line horizontally through the anal canal
      • If external opening is anterior to this line fistula runs directly into the canal
      • If external opening is posterior to this line fistula curves to post midline of canal

Causes

Clinical Features

  • Fistulous tract open: Persistent, painless, blood-stained, mucous, malodorous discharge
  • Fistulous tract blocked: Bouts of inflammation that are relieved by spontaneous rupture
  • Abscess
    • Throbbing pain that is constant and worse with sitting, moving, defecation
    • May be only sign of fistula
  • Fistulous opening
    • Adjacent to anal margin suggests superficial connection (e.g. intersphincteric region)
    • Distant from anal margin suggests deeper, more superior abscess

Differential Diagnosis

Anorectal Disorders

Non-GI Look-a-Likes

Evaluation

  • Endocavitary ultrasound with 3% hydrogen peroxide for definitive diagnosis

Management

  1. Ill-appearing
    1. Analgesia
    2. IVF
    3. Antibiotics
    4. Urgent surgical consultation
  2. Well-appearing
    1. Antibiotics
      1. Ciprofloxacin 750mg PO BID AND metronidazole 500mg QID x7d
    2. Outpatient surgery referral
      1. Improperly excised fistulas may result in permanent fecal incontinence
    3. Spasm treatment
      1. Nitroglycerin, Lidocaine
      2. Sitz baths

See Also

References