Examination
of the anus
This requires careful attention to circumstances. The examining couch should be of sufficient height to allow easy inspection and access for any necessary manoeuvres. A good light is mandatory. The Sims (left lateral) or the lithotomy position is satisfactory: the latter is less convenient for an elderly patient and can cause social embarrassment to young women. A protective glove should be worn. The patient should be relaxed and able to co-operate. A few quiet words from the doctor can prevent many loud ones from the patient.
Inspection
With the buttocks opened, the anus is
inspected. Note is made of
any lesions, e.g. inflammatory skin changes, haemorrhoids, fissure
(‘sentinel
pile’) or fistula.
The patient is
asked to strain
down before inspection is concluded.
Digital
examination with the index finger
A good lubricant is necessary
neither too little
nor too much.
Any secretions should be sampled before applying lubricant to the anal verge.
Extreme
gentleness should be the rule so that pain is not caused. Painful spasm of the
anal sphincters is confirmation of a hidden fissure if the history is
suggestive.
The
examination should check normal, as well as abnormal, structures according to
the following plan:
•
intraluminal:
— normal: faeces,
— abnormal: polyp or carcinoma;
•
intramural:
— normal: sphincter muscles and anorectal angle,
— abnormal: carcinoma or leiomyoma;
•
extramural:
— normal: perianal structures,
— abnormal: abscess.
Discharge
After withdrawal, the
finger is
examined for mucus, pus, blood
and abnormal faecal
material.
Proctoscopy
(Fig. 61.10)
This examination is of great importance. Either the Sims position with the buttocks elevated on
a small cushion, or the knee—elbow position (Fig. 61.11) may be used. The lower third of the rectum, the anorectal junction and the anal canal can be
inspected as the instrument is withdrawn slowly. The patient should also be asked to strain during withdrawal as by so doing
an internal intusussception may be made
visible. Minor procedures can be carried out through this instrument, e.g. treatment of haemorrhoids by
injection or
banding (see below)
and biopsy.
Sigmoidoscopy
(Chapter 60)
Although this is a strictly an examination of
the rectum and
lower sigmoid colon, it should be
carried out even
when an anal lesion has been confirmed.
Rectal pathology,
e.g. colitis or
carcinoma, is frequently the cause of an anal lesion, e.g. fissure or haemorrhoids. Not infrequently, rectal
pathology is found
that is
independent of the
anal lesion
and which requires
treatment.
Special
investigations
These are discussed above.
Physiological studies
Manometry
Electrophysiology
Proctography
Endoluminal ultrasound