Anal Incontinence
The definition of anal incontinence is the inability to defer defaecation to an appropriate time and place. Population studies estimate the prevalence of anal incontinence in the community to be around 4%. Many causes of incontinence can be treated by either surgical correction of sphincter defects or sacral nerve stimulation to treat neuropathic disorders. Rectal prolapse is another cause of incontinence and manometry, rectal sensory volumes and ultrasound can aid in diagnosing this under reported problem.
Investigations to delineate the causes of incontinence include manometry to assess anal tone and squeeze pressures, pudendal nerve testing to ensure normal nerve transit and endoanal ultrasound to map sphincter defects that may be amenable to surgical repair
SUGGESTED INVESTIGATIONS:
Endoanal Ultrasound, Pudendal Nerve Testing, Anorectal Manometry
Anal Sepsis and Fistula
Most perianal sepsis and cases of fistula can be simply treated with surgical drainage or laying open the fistula tract. Some fistulae may be complicated with multiple tracts or high internal openings. In these cases incontinence may occur with simple lay open techniques.
Endoanal ultrasound is the best way to map out complex anal fistula and assess how much sphincter is involved. It enables the operating surgeon to decide whether it may be more appropriate to attempt a sphincter conserving procedure. Preoperative manometry is useful to document sphincter pressures
SUGGESTED INVESTIGATIONS:
Endoanal Ultrasound; anorectal manometry
Low Rectal Tumours / Polyps / Cancer
Endorectal ultrasound gives useful information on low villous rectal tumours. It can accurately identify breaches in the submucosa to discriminate between benign villous adenomata and early rectal cancers. It enables identification of mesorectal lymph nodes as well as cancer penetration through the full rectal wall that may indicate the need for preoperative radiation and chemotherapy prior to surgery for rectal cancers. It is also useful in follow-up of those patients who have previously undergone a transanal local excision of their cancer.
SUGGESTED INVESTIGATIONS:
Endorectal Ultrasound, manometry if concerns with potential for incontinence after surgery
