A patient's rectum and anus can cause him much disability and discomfort. In the tropics he can have most of the diseases which are seen elsewhere, but with a different frequency, and with a few extra ones. You should have little difficulty treating anorectal abscesses (5.13) and fistulae (22.2), piles (22.4), fissures (22.7), pilonidal sinuses (very rare in Africans, 22.8), prolapse of the rectum (22.9), juvenile polyps (22.10), lymphogranuloma venereum (22.10), and some cases of imperforate anus (28.6).
Although the anus is a particularly infected area, so that any surgical wounds near it are sure to become infected, the infection seldom spreads, so that they readily heal[md]if you let them granulate from the bottom up[md]make sure your nurses understand this. Don't attempt primary suture, and instead make wide, shallow saucer-like wounds. Don't let his subcutaneous tissues or his skin edges fall together and unite prematurely, before the bottom of his wound has healed. A shallow, open wound with trimmed edges heals better than one with much redundant skin and fat.
PHYSIOLOGY. The purpose of a patient's anus is to keep him continent. Its failure to do this is a social disaster. Continence is mostly maintained by his external sphincters and his levator ani, especially its deep puborectalis part, which forms a sling at his anorectal line, in the angle between his anus and his rectum. The tone in his external sphincters is increased by reflex and voluntary contraction. His internal sphincter, which is under autonomic control, is less important, but helps to keep his anal canal closed and empty. In painful conditions, both his sphincters are in spasm. The lower part of his anal canal is sensitive enough to let him know what is in his rectum[md]nothing, gas, liquid, or solid. Receptors in the smooth muscle of his upper rectum and the voluntary muscle of his pelvic floor let him know when his rectum is dilated. Goligher JC, ''Surgery of the anus, rectum and colon'. (4th edn 1980). Balli[gr]ere Tindall. PROCTOSCOPE, Gabriel, 64[mu]25 mm, one only. This is the standard instrument for examining the rectum. You will also find an ordinary Sims' speculum useful for examining the anal canal under general anaesthesia.
SPECULUM, bivalve, Goligher pattern with detachable third blade, one only. Use this for doing minor rectal operations, such as division of the internal sphincter.
SIGMOIDOSCOPE, Strauss, 330 mm, Luer fitting, in case with bellows, cord and standard endoscope bulb (35.1) complete with biopsy forceps, etc., one only. Keep sigmoidoscopes and proctoscopes in a case so that their various parts don't get lost.
SPONGE HOLDER, for sigmoidoscope, 430 mm, one only.
FORCEPS, for biopsy through sigmoidoscope, Officer pattern, one only. These are the most expensive part of the outfit. If necessary, you can use them to remove foreign bodies from the oesophagus, or even from the urethra.
SUCTION TUBE FOR SIGMOIDOSCOPE, one only. You can make this from a piece of ordinary copper tube, 15 cm longer than the sigmoidoscope, with a right angle bend at one end.
BELLOWS, spare for Strauss sigmoidoscope, Luer fitting, one only.
BULBS, endoscope, standard (35.1), small fitting, ten only. Endoscope bulbs are very easily blown.
BATTERY BOX, for endoscopes, holding D type dry cells, one only. This must be the same voltage as the standard endoscope bulbs, and have a lead which fits the endoscopes.
PROBE, medium-sized, malleable silver, one only.
DIRECTOR, probe-pointed, one only. This has a groove on it. Pass it through a fistula and then cut down on the groove.
Fig. 22-1 THE ANORECTUM. A, an anatomist's view to show the bony pelvis (1), inside which is obturator internus (2). Below the pararectal fossa (3) lies the pelvirectal space (4). This is separated from the ischiorectal fossa (5) by the levator ani muscle (6). Sphincter ani externus has three parts, a subcutaneous part (7), a superficial part (8), and a deep part (9). Inside the external sphincter lies the internal sphincter (10). This is continuous with the circular muscle of the gut (11), outside which is the longitudinal muscle (12). Two other muscles are also shown, semitendinosus (13), and gluteus maximus (14). The rectal venous plexus (15), is drained by the superior rectal vein (16) and the inferior rectal vein (17).
B, a proctologist sees things more simply and has three reference points. His first is the anal verge (18), where the anal and perianal skin join. His second is the pectinate line (also called the dentate line) (19), where the anal columns (20) and sinuses end. Red, loosely-attached rectal mucosa lies above this line, and pale, tightly-stretched anal lining lies below it. His third reference point is the anorectal line (21), which is the palpable upper border of the complex of anal sphincters. This is something you can easily feel with your examining finger, provided the patient has adequate muscle tone, and has not been anaesthetized and given a relaxant. It is about 2 cm further in than the pectinate line, and the rectum balloons out above it, as shown in D.
Note that the external sphincter (7) comes down a bit lower than the internal one (10).
The anal glands (22), are an important site of infection, and the origin of fistulae and sinuses. They open into the crypts just above the pectinate line.
C, a view of the rectum to show how the puborectalis muscle pulls the anorectal junction upwards and forwards when it contracts. You can easily feel it doing this when you do a rectal examination. During defaecation, it relaxes completely. Increased intra-abdominal pressure pushes the anterior rectal wall down, and so closes the anal canal and prevents incontinence.
D, the relation of the anorectal line to the external sphincter. A, after ''Gray's Anatomy', 8.127 (Churchill Livingstone). B, after MacLeod JH, ''A Method of Proctology', Fig. 1.1. Harper and Row, with kind permission. C, and D, kindly contributed by Brian Hancock. THE PECTINATE LINE AND THE ANORECTAL LINE ARE LANDMARKS
THE GENERAL METHOD [s8]FOR THE ANUS AND RECTUM EQUIPMENT. A rectal tray containing proctoscopes, finger cots or gloves, long cotton-tipped applicators, and testing materials for occult blood. If you are going to pass a sigmoidoscope, you may need a suction tube and a sucker.
PREPARATION. Put a drape over the patient and keep the instruments out of his sight. Tell him what you are going to do, and explain that you will not hurt him. If some pain is necessary, warn him. Be gentle, don't hurry, and use warm instruments.
Lie him on his side with his buttocks extending well over the edge of the table, as in A Fig. 22-2. Flex his hips fully, but keep his knees at 90[de] so that they are out of your way. It is convenient to have his right upper hip and knee a little more flexed than his left.
DIGITAL EXAMINATION [s7]OF THE RECTUM Draw his buttocks apart and look at his anal region for skin tags, lumps and the openings of fistulae (B). Feel any abnormalities, such as the tracks or openings of fistulae, or tumours (C).
Lubricate the end of your finger well. Insert it so that its larger broad dimension lies in the anteroposterior axis of his anal canal. When you touch the sphincter, it will contract. Wait, give it a few seconds to relax, and then press firmly and gently in the axis of his anal canal. Keep pressing, until you can feel your finger suddenly slip easily into his anus. Note the tone of the sphincter.
As you put your finger into his anus, feel for lesions below and above his anorectal line. Then palpate the entire circumference of his anus between your two fingers (E).
In a man feel each of the two lobes of his prostate separated by a median furrow.
In a woman, look to see if she has a rectocoele, feel her cervix and uterus rectally, and feel for swellings in her rectovesical pouch.
Sweep your finger all round the patient's pelvis and examine his coccyx between two fingers (F).
Finally, if you suspect an intraperitoneal mass, a bimanual recto-abdominal examination may be useful in a man (G), and a vagino-abdominal one in a woman.
Fig. 22-2 EXAMINING A PATIENT'S RECTUM. A, have his knees well flexed and his buttocks over the edge of the couch. B, start by looking. C, then feel. You may feel the track of a fistula. D, feel his anal canal as you insert your finger. E, feel all round his anus. F, feel his coccyx. G, if necessary, examine his abdomen between your two hands. After MacLeod JH, ''A Method of Proctology', (179) Figs. 2-1, 2-8, 2-9, Harper and Row, with kind permission.
PROCTOSCOPY. Examine his anus with your finger first. Lubricate the proctoscope and push it firmly in the direction of his umbilicus. Examine the lining of his anal canal as you withdraw it[md]slowly, and looking for piles as you do so.
SIGMOIDOSCOPY Do a sigmoidoscopy just after he has defaecated normally, or after he has had an enema. There is no need for a general anaesthetic, unless you fail without one and the examination is essential (as for carcinoma). If you are clumsy, you can perforate his gut, so: (1) Always do a digital examination first. (2) Never push a sigmoidoscope further in, if you cannot see the lumen in front of it. Follow the lumen at all times. (3) Never force it. If there is a pocket or a blind area in the way, withdraw it a little, and then advance it again. Your main aim while inserting it is to do so successfully. Do most of the examining as you withdraw it.
Ask him to breathe in and out while you gently insert it, lubricated and warmed with its inserter in place. You will feel the resistance of his anal sphincter suddenly diminish (B, in Fig. 22-3) as it enters his rectal ampulla.
While you look where it is going, turn it 90[de] posteriorly (C), as you gently manipulate it past the mucosal valves of his rectum. While you insert it, gently pump in enough air to distend the lumen in front of it. Don't blow his sigmoid up too much, or he will feel urgency and cramps.
The first 12 to 15 cm, as far as his rectosigmoid junction is usually easy. You will see his smooth rectal mucosa giving way to the concentric rugae of his sigmoid colon. At this point his gut passes over his sacral promontary, and may turn in any direction. Proceed anteriorly and to the left. You should be able to reach 25 or 30 cm, but don't force it. Be sure you can distend his gut with air, before you push the sigmoidoscope further in.
If you find much stool, send him to the lavatory; if that fails give him an enema, and try again later.
Rotate the sigmoidoscope, as you withdraw it, so that you inspect every part of his mucosa. Be careful to examine the posterior wall of his rectal ampulla. This lies at 90[de] to his anal canal, and you can easily miss it. Remove some stool, and test it for occult blood.
Fig. 22-3 PASSING A SIGMOIDOSCOPE (A) enables you to inspect the last 25 cm of a patient's colon. With your finger you can only feel the last 8 cm. B, introduce the sigmoidoscope, pointing it towards his umbilicus, and when it is through his anal sphincter (C) swing it backwards. After MacLeod JH, ''A Method of Proctology', (1979), Figs. 2-12 to 2-14. Harper and Row, with kind permission.
PREOPERATIVE CARE [s7]FOR ANAL OPERATIONS Do a sigmoidoscopy before all anal operations to exclude coexisting tumours and inflammatory bowel disease. For this to be possible, his bowel must be empty, so give him a small enema or a glycerine suppository preoperatively.
POSTOPERATIVE CARE [s7]AFTER ANAL OPERATIONS DRESSINGS are important. Dress an open anal wound with flat pieces of gauze, soaked in hypochlorite (''Eusol' or ''Milton' 15 ml to a litre of water), or some other antiseptic or salt solution. Cover the whole raw surface with a flat piece of gauze. Tuck an edge of the gauze into any flat crevices. Insert a corner of the gauze into any extension of the wound towards his anal canal. Use more gauze to fill out the hollow of the wound up to the level of the surrounding skin.
Finally, apply more gauze and wool to the surface, and hold the whole dressing with a T-bandage.
BATHING is more convenient than irrigation. Sit him in a large bowl containing warmed salt solution equivalent to full- strength or half-strength saline.
BOWEL ROUTINE. Give him 15 ml of liquid paraffin twice daily from the day of the operation. If he has not opened his bowels by the evening of the second postoperative day, counting the day of the operation, give him 3.5[nd]5 ml of liquid extract of cascara, or some similar purgative. If his bowels do not act the following morning, do a rectal examination to see what the problem is; his rectum may be empty. If his faeces are impacted give him 850[nd]1000 ml of a soap and water enema, through a tube, a funnel, and a well-lubricated rubber catheter. Ask him to retain the enema as long as possible before using a bedpan. The dressing will probably come away with his bowel action. Give him a bath, and redress his wound.
Continue with 15 ml of liquid paraffin each evening, for a week only. If you continue too long, there are numerous side effects, such as the malabsorption of fat-soluble vitamins, and paraffinomas; also his anus may stenose because it is never dilated by a normal stool.
Fig. 22-4 PROCTOLOGY. A, a diagram for recording abnormalities around a patient's anus. This has 3 lines, an inner one for the anorectal line, a middle wavy one for the pectinate line, and an outer one for the anal margin. Record your findings in relation to these 3 lines. Here, the diagram records the sites of the three primary piles, and the common sites of two secondary ones. B, arrangements for operating on a patient's anus. You must also have a light on a stand which will direct its beam horizontally into the wound. C, a T-bandage before the operation, and D, the bandage tied up after it. After Goligher JC, ''Surgery of the Anus Rectum and Colon', (4th edn. 1980) Figs. 64 and 65, Bailli[gr]ere Tindall, with kind permission.