1. Anal canal & rectum
Anatomy
physiology

2. Rectum + Anal Canal Rectum Anal Canal pg 632 descends into pelvis
no teniae coli
longitudinal muscle layer complete
rectal valves
Anal Canal
passes through levator ani muscle
releases mucus to lubricate feces
Internal anal sphincter
involuntary, smooth m.
External anal sphincter
voluntary, skeletal m.
Stratified squamosal epithelium at lower half
pg 632

3. Perianal and Perirectal Anatomy
Levator ani muscle
Anorectal
ring
Deep external sphincter and
Puborectalis muscle
Anorectal ring – internal sphincter thickens and the puborectalis muslce can be palpated digitally
For a distance of about 1 cm above the dentate line there is an epithelial linining may be columnar, transitional, or stratified squamous know as the transitional or the cloacogenic zone
Rectal prolapse – transabdominal proctopexy
Transansal via perineal rectosigmoidectomy or via a modified delorme procedure
Conjoined longitudinal
muscle
Subcutaneous external
sphincter

4. Defecation Reflex Stretching of rectum wall initiates reflex
Spinal cord - parasympathetic signals sigmoid colon + rectum to contract + anal sphincter to relax (involuntary)
If not ready-reflex ends- rectum relaxes
Reflex initiated again until you go!
Contraction of abdominal muscles, levator ani + diaphragm assists defecation (voluntary)

5. Pilonidial Disease (Nest of Hair)
Aetiology:
1- Congenital Theory:
2- Acquired Theory:
Sitting the buttocks take the wt…..hair broken off by friction …hair from nape of neck ,back or buttocks ….collect in the cleft of the nate .
The reasons which support the Acquired T.:

6. The reasons which support the Acquired T.:
1- interdigital
2- age incidence.
3- no hair follicles
4- dead hair
5- most commonly affect men and hairy
6- recurrence is common

7. Pilonidal Disease

8. Pilonidal Sinus Clinical features Male >female :4 /1
Common adolescence &3rd decade
White races
Acute…. Painful swelling
Chronic …. Discharging sinus
ON exam:
Chronic or recurring sinus …1st piece
of coccyx
Blood stained foul odour ,tuft of hair
Acute exacerbation ..tender swelling
Secondary opening

9. Differential diagnosis
1- Fistula in ano
2-post anal dermoid cyst
3-postanal dimple

10. Treatment Conservative treat.: - cleaning out track - frequent washing
- long sitting
Acute exacerbation (abscess): rest ,BSAB, bath ,drainage
Operations:

11. Operations:
Lay open tracks……suture the edge to skin Marsupial sing the sinus
Excise all the Tracks and suturing with drain
Excise all the Tracks and pack the wound then dressing (granulation tissue)
Some injecting methylene blue
Lateral incision to midline
Rotational flap
Bascom technique