3. anorectal disease

Rectal cancer → CT + PELVIC MRI → often neoadjuvant therapy before surgery if locally advanced.

dentate (pectinate) line

What structure separates the change between the skin of the anus and mucosal lining of the rectum?

visceral innervation (autonomic)

_{^{primarily through the inferior hypogastric (pelvic) plexus.}}

• _{^{Sympathetic: L1–L2 → lumbar splanchnic/hypogastric pathways}}

• _{^{Parasympathetic: S2–S4 pelvic splanchnic nerves}}

*** NO PAIN

innervation above the dentate

• Somatic: S2–S4

• Inferior rectal nerve → pudendal nerve*

• 
  

• Very sensitive to pain, temperature, and touch

innervation below the dentate

columnar epithelium

cell type of anus above dentate

stratified squamous

cell type of anus below the dentate

smooth muscle (involuntary)

muscle type of the internal anal sphincter

skeletal muscle

(voluntary, pudendal nerve)

muscle type of the external anal sphincter

puborectalis muscle

muscle that creates the anorectal angle and maintains stool continence

anorectal angle

Region of rectum that passes through pelvic diaphragm

puborectalis

relaxation of this muscle allows defecation

Anal columns of Morgagni

Vertical mucosal folds above dentate line

House hemorrhoidal vessels

80-100 degrees

Memory:

~90° holds it;

>110° lets it go.

what is a normal anorectal angle?

Increased (straightened) → incontinence

Decreased → constipation/obstruction

what is the significance of the anorectal angle

Vaginal delivery (levator ani injury)

Aging

Chronic ↑ intra-abdominal pressure (obesity, constipation)

Pelvic surgery

structural causes of pelvic floor disorders

Pudendal nerve damage

Spinal cord disease

Diabetes (autonomic neuropathy)

neurologic auses of pelvic floor disorders

↑ Intra-abdominal pressure

→ bladder pressure exceeds urethral closure pressure

→ urine leakage

mechanism of stress incontinence

detrusor overactivity

mechanism of urge incontinence

retention--> leakage

mechanism of overflow incontinence

BPH, neurogenic bladder

causes of overflow incontinence

impaired mobility/cognition (ex: dementia)

cause of functional incontinence

External sphincter injury (OB trauma)

Pudendal neuropathy

Rectal prolapse

Chronic diarrhea

primary causes of fecal incontinence

Type	First-line treatment {conservative}
Stress	Pelvic floor (Kegel) exercises + weight loss/lifestyle modification
Urge	Bladder training + pelvic floor exercises
Overflow	Treat retention/underlying cause → catheterization if significant retention
Functional	Scheduled/prompted voiding + address mobility/environmental barriers

first line management of incontinence

stress-

urge -

overflow -

functional -

• Stress: midurethral sling / other procedures; pessary can be used in selected patients

• 
  

• Urge: antimuscarinic (e.g., oxybutynin) or β3 agonist (mirabegron)

• 
  

• Overflow from BPH: treat BPH (e.g., tamsulosin) and relieve significant retention

second line tx for incontinence

stress -

urge -

overflow -

urge incontinence

involuntary leakage of urine with a sudden, strong desire to urinate

pessary

appliance of varied form, introduced into the vagina to support the uterus or to correct any displacement

sling procedures

surgical procedures for stress incontinence

Weak stream

Hesitancy

Incomplete emptying

Overflow incontinence

clinical features of urinary obstruction

foley catheter

acute treatment of urinary obstruction

α1-blockers (tamsulosin)

5α-reductase inhibitors (finasteride)

primary pharm treatments of BPH--> urinary obstruction

TURP

_{^{= widens the prostate thru the pee pee}}

surgical treatment of BPH for urinary obstruction

1. Mucosal prolapse

   • ^{Only the rectal mucosa protrudes}

   • ^{Often associated with hemorrhoids}

2. Internal rectal prolapse (rectal intussusception)

   • ^{Rectum telescopes into itself}

   • ^{Does not protrude through the anus}

3. Complete/full-thickness rectal prolapse

   • ^{Entire thickness of rectal wall protrudes through anus}

   • ^{Classic finding: concentric/circular folds}

---

_{^{Rectal prolapse → concentric folds}}

_{^{Prolapsed internal hemorrhoids → radial folds}}

_{^{Memory: Rectal = Rings; Hemorrhoids = Radial.}}

name the types of rectal prolapse

Chronic constipation/straining

Pelvic floor weakness

Neurologic disease

Elderly women (most common demographic)

primary causes of rectal prolapse

concentric: rectal prolapse

radial folds of prolapsed: hemorrhoids

concentric vs radial anal folds

rectal prolapse

“Something coming out” of rectum

Concentric folds

Fecal incontinence

Mucus discharge

Stool softeners

Fiber

Pelvic floor therapy

conservative treatment of rectal prolapse

definitive surgery for rectal prolapse

Perianal abscess

Fistula-in-ano

Hidradenitis suppurativa

Crohn's perianal disease

---

_{^{quick associations:}}

_{^{Painful fluctuant mass → Abscess → I&D}}

_{^{Chronic draining opening after abscess → Fistula-in-ano}}

_{^{Recurrent groin/perineal boils + sinus tracts + scars → Hidradenitis}}

_{^{Multiple/complex perianal fistulas + GI symptoms → Crohn's}}

inflammatory causes of perianal pain

anal fissure

most COMMON cause of severe pain with defecation

thrombosed external hemorrhoid

hard, painful, irreducible, blue mass protruding from the anal canal.

pilondial disease

a hair-containing abscess/sinus in the intergluteal cleft

levator ani syndrome

idiopathic dull ache possibly resulting from dysmotility of the muscles supporting the rectum and anus

bright red blood on toliet paper,

painless

bleeding associated with internal hemorrhoids

anoscopy

exam indicated for internal hemorrhoids

rubber band ligation (internal)

procedure in management of internal hemorrhoid

excision if <72 hours

mild or >72 hours — conservative mngmt

-

_{Conservative treatment}

• _{^{NSAIDs/analgesia}}

• _{^{Sitz baths}}

• _{^{Stool softener / fiber}}

• _^Hydration

• _{^{Avoid straining}}

management of thrombosed external hemorrhoid

small amount of bright red blood

painful asf

bleeding associated with anal fissure

posterior midline

most common location of anal fissure

fiber, sitz bath

second line: nitroglycerin or CCB

first line management of anal fissure

a surgical procedure in which a small portion of the internal anal sphincter muscle is cut to relieve pressure and promote healing in patients with chronic anal fissures.

perianal fistula

a small, abnormal tunnel connecting an infected anal gland to the skin near the anus

• commonly causing pain, swelling, and persistent pus-like discharge

perianal fistula

-chronic anal drainage

-mild pain, minimal bleeding

Surgical (fistulotomy/seton)

Treat underlying Crohn’s if present

treatment of perianal fistula

perianal abscess

collection of infection within or adjacent to the perianal space

-severe, constant, throbbing pain

-fluctuant erythematous mass

🚨 Immediate incision & drainage (DO NOT delay)

Antibiotics if immunocompromised

treatment of perianal abscess

Midline sacrococcygeal (NOT anal)

typical location of pilonidal disease

Hair + debris → sinus

cause of pilondial disease

Acute: I&D

Chronic: excision

treatment of pilonidal disease

apocrine gland obstruction

what causes hidradenitis suppurativa

Antibiotics

Biologics (severe)

Surgery if refractory

treatment of hidradenitis suppurativa

perianal condyloma

most commly HPV 6 & 11

(high ca risk 16,18 —> SCC)

painless cauliflower like lesions

_{(anal warts)}

Topical (imiquimod)

Cryotherapy / excision

treatment of perianal conduloma

fistulas, abscesses, fissures

perianal findings of Crohn's disease

HPV, immunosuppression

primary risks of anal tumors

Chemoradiation (NOT surgery first)

management of anal tumors

evaluate internal hemorrhoids, tumors

what is anoscopy used for?

proctoscopy

procedure for looking at the anus and rectum;

deeper rectal pathology than anoscopy