الفهرس 
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Abstract
Anorectal motility disorders considered one of the most important subjects
in the whole field of the gastrointestinal tract motility because they can
disrupt the life style. The anorectal function depends on the complex
interrelation of sensory and motor function, so that diagnosis of motility
disorders of the anorectum requires combination of a careful history,
physical examination and use of special physiological and image
techniques 1l1ce anoredal manomefW, ~ftdO!lIl!l1 uItrnound,
electromyogram and pudendal nerve latencies in determining the line of
treatment in the benign anorectal diseases.
Fecal incontinence is a disabling problem, which may be due to a
mechanical defect in the muscle, inadequate innervations of the sphincter
mechanism or idiopathic causes, by the use of the manometric study we can
differentiate between mechanical and neurogenic defects where the
anorectal manometry can document reduced resting and squeeze pressure
as well as sphincter length in incontinenent quadrants.
Most patients have low resting anal pressure and abnormal external anal
sphincter electromyograms suggesting a neuropathy. But abnormally
elevated rectal pressures have been recorded in some patients, so that rectal
pressures exceeds anal canal pressure intermittently thus causing leakage.
Many patients with incontinence also have an obtuse anorectal angle if the
angle is obtuse and anal canal pressures are adequate, incontinence does
not occur. Conversely if the angle is obtuse and the sphincter is
incompetent, incontinence is inevitable. If the angle is normal and the
sphincter is inadequate, continence to solid stool is usually maintained.
These results can be confirmed by transanal ultrasound which is the most
sensitive method for documenting sphincter injury where by a cross section
image of the sphincter is obtained on each rotation of the transducer and
allows evaluation of the anal sphincter muscle in three dimensions as the
probe is withdrawn from the rectum.
Also the electromyography can help in diagnosis of incontinence by
measures the number of phases in the spontaneous motor unit potential of
the resting external sphincter muscle where an increase in the number of
phases in each motor unit potential reflects evidence of injury to the
terminal branches of the pudendal nerve. This is very sensitive method of
detecting pudendal nerve injury but it is extremely painful to the patient.
And the nerve conduction studies of the pudendal and spinal nerves also
can help in diagnosis of the neurogenic causes as the pudendal nerve
terminal motor latency can measure the conduction velocity of the action
potential through the terminal 4 cm of the pudendal nerve between
Aclock’s canal {site of the pudendal nerve} and the external sphincter
where any delay in conduction means an injury to the fast-conducting
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fibers of the nerve and this injury usually is the result of stretch, direct
trauma or systemic disease .
The efficacy of the anorectal manometry in cases of anal fissure becomes
well established where by the anal canal pressure can be estimated
preoperatively to determine which type of operation to be done as, this may
be either internal sphincterotomy with fissurectomy if the anal canal resting
pressure is high or fissurectomy alone if the anal canal resting pressure is
normal or low. As the spasm is not a constant fmding, incision of the
internal sphincter in a patient with normal tone or in a patient with deficient
striated muscle may lead to fecal soiling.
On the other hand, in cases of advanced disease with marked anal spasm a
standard sphincterotomy may be ineffective and the fissure may recur.
Therefore, grading the extent of the internal sphincterotomy according to
the degree of anal spasm found at preoperative anorectal manometry is
suggested.
Haemorrhoidal disease patients can be classified into two main groups, the
high manometric findings group and the normal or low manometric
findings group. The first group who have high anorectal manometry
findings; this group will be beneficially managed if they will be managed
by internal sphincterotomy in addition to classic hemorrhoidectomy.
The second group those who have normal or low anorectal manometric
findings, this group will be in harm if they are exposed to mmeeded manual
dilatation or additional sphincterotomy as they may develop fecal soiling or
incontinence. So the anorectal manometry cousidered an important
preoperative measure to choose the proper line of management for
Haemorrhoidal disease patient.
The causes of constipation may be a defect in fecal propulsion due to
dysmotility of the colon, rectum or whole gut or due to a defect in fecal
expulsion i.e. obstructed defecation. By the use of anal manometry and
EMG studies of the sphincter, pelvic floor muscle will help much in the
diagnosis and aid the management. Also, idiopathic constipation may be
due to irritable bowel syndrome that has short transit time and pain from
hyper segmentation or due to slow transit and a hypo motile sigmoid colon,
where these can be diagnosed by the anal manometry and
electromyography in a variety of ways. The myoelectrical activity of the
sigmoid can be measure using surface electrodes at operation or by needle
electrodes introduced into the bowel wall at sigmoidoscopy. Sigmoid
myoelectrical activity is increased in patients whose constipation is due to
diverticular disease or the irritable bowel syndrome. Myoelectrical activity
is increased in slow transit constipation and increased segmentation is
responsible for slowing colonic transit.
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Rectal prolapse is a relatively common condition. which is distressing as it
is associated with fecal incontinence in 80% of patients. Incontinence is
particularly prevalent in elderly patients. In the rectal prolapse with
incontinent there is lower resting anal pressure than prolapse with continent
and the use of preoperative anal pressures manometry study are of
predictive value in identifying patients who are likely to remain incontinent
after rectopexy.
Single fiber electromyography of the external sphincter and puborectalis in
incontinent patients is typical of nerve damage. Pudendal nerve terminal
motor latency is prolonged, particularly in incontinent patients and provide
objective evidence of pudendal nerve injury and allow some prediction of
outcome after repair, nerve injury indicates poor recovery of sphincter
function.
” .’ l” .:’ I • from the above we can know the importance of studymg of anorectal
pressure, endoanal ultrasound, electromyogram and pudendal nerve
latencies in determining the line of treatment in the benign anorectal
diseases.