Suzie, Robz, Gemmy

I.5 – Colon, Rectum, and Anus (Lecture)Dr. Mata

June 9, 2013EMBROYOLOGY

The embryonic gastrointestinal tract begins developing during the 4th week of gestation

The primitive gut is derived from the endoderm and divided into three segments Foregut Midgut* Hindgut*

*contribute to the colon, rectum, and anus

MIDGUTDevelops into the

small intestine, ascending colon, and proximal transverse colon

Receives blood supply from the superior mesenteric artery

During the 6th week of gestation, the midgut herniates out of the abdominal cavity, and then rotates 27ocounterclockwise around the superior mesenteric artery to return to its final position inside the abdominal cavity during the 10th week of gestation

MIDGUTDevelops into the

distal transverse colon descending colon rectum and proximal anus

all of which receive their blood supply from the inferior mesenteric artery

during the 6th week of gestation, the distal-most end of the hindgut, the cloaca, is divided by the urorectal septum into urogenital sinus rectum

DISTAL ANAL CANALderived from ectoderm and receives its blood supply

from the internal pudendal artery the dentate line divides the endodermal hindgut from

the ectodermal distal anal canal

ANATOMY the large intestine extends from the ileocecal valve to

the anus it is divided anatomically and functionally into

colon rectum anal canal

the 1st 6 cm of the large intestine just below the ileocecal valve, the ascending colon, and the hepatic flexure form a surgical unit, the right colon

Figure 1. Colon anatomy and measurements

HEPATIC FLEXURE

located under the 9th and 10th costal cartilages in the vicinity of midaxillary line

gallbladder is located anteriorlyduodenum is located posteriorly

ASCENDING COLONThe ascending limb of the right colon is fused to the

posterior body wall and covered by the peritoneumFused variations

Deep lateral paracolic groove to the persistence of an entire ascending mesocolon

TRANSVERSE COLONThe transverse colon hangs in a U or V-shaped curveThe transverse mesocolon is formed by a double

peritoneal foldThe 2 are fused at “X” to form the transverse mesocolon

containing the middle colic artery and vein

DESCENDING COLONCovered anteriorly and on its medial and lateral sides by

peritoneum Has no mesenteryMobilization of the ascending colon is accomplished by

incising the peritoneal reflection at the left gutter along the “white line of Told”

SIGMOID – S shaped2 portions

Iliac portion – fixed and located at the left iliac fossa

Pelvic portion – mobileBegins at the iliac crests and ends at the 3rd sacral

vertebra

RECTUMThe junction between the sigmoid colon and the rectum

has been variously described: A point opposite the left sacroiliac joint Level of the 3rd sacral vertebra Level at which sacculations and epiploic appendages

disappear and taeniae broaden to form a complete muscle layer (long transition)

Level at which the superior rectal artery divides into the right and left branches

Construction with anterior angulation (proctoscopy) Transition between rugose mucosa of the colon and

smooth mucosa of the rectumPosteriorly, the presacral fascia separates the rectum

from the presacral venous plexus and pelvic nervesAt S4, the retrosacral fascia (Waldeyer’s fascia)

extends forward and downward and attaches to the fascia propria at the anorectal junction

Anteriorly, Denonvilliers’ fascia separates the rectum from the prostate and seminal vesicles in men and from the vagina in women. The lateral ligaments support the lower rectum

The entire upper 1/3rd of the rectum is covered by peritoneum

The mesorectum, which suspends the rectum from the posterior body wall, comes off more laterally, leaving bare progressively more of the posterior rectal wall

The peritoneum finally leaves the rectum and passes anteriorly and superiorly over the posterior vaginal fornix and the uterus in females or over he superior ends of the seminal vesicles and the bladder in males

This creates a depression, the rectouterine or rectovesical pouch With infection, this may become filled with pus

SPACES OF THE ANUS AND RECTUMPelvirectal space

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I.4a – Colon, Rectum, and Anus (Lecture)

Ischioanal (ischiorectal) space Intersphincteric spacesSubcutaneous spaceCentral spaceSubmucousspace

PERITONEAL LOCATIONS

Figure 2. Peritoneal Locations

ARTERIAL SUPPLY OF THE COLON

Figure 3. Arterial Supply of the colon

SMA BRANCHES TO THE COLONMiddle colic arteryRight colic artery Ileocolic arteryMeandering Artery of Riolan – communicating between

Middle colic and IMA

MEANDERING ARTERY OF RIOLAN

*blue arrowsSMA

*blue arrows

IMA If the inferior mesenteric artery is divided at “a” above,

the last full anastomosis, collateral circulation toward the rectum is still possible

Division at “b” would interrupt the collateral circulation

SUDECK’S CRITICAL POINTSudeck described a point on the superior rectal artery at

which ligation of the artery would not devascularize a long rectosigmoid stump

This point is just above the origin of the last sigmoid artery

“Ligation below the Sudeck’s point would devascularize the rectum” Not critical as it was thought to be

The concept of Sudeck’s critical point fails to recognize 2 other sources of blood to the rectum

ALTERNATIVE BLOOD SUPPLYOne is the intramural network of arteries in the

submucosal layer of the wall and the other is from collaterals

Branches of the inferior vesical arteryArteries supplying the levator ani muscleThe middle sacral arteryThe posterior retroperitoneal arterial plexus uniting the

parietal and visceral circulationThe inferior rectal artery is responsible for the arterial

blood supply of the distal 2 cm of the anal canal

MARGINAL ARTERY OF DRUMMONDComposed of a series of anastomosing arcades between

branches of the ileocoloc, right colic, middle colic, left colic, and sigmoidal arteries

These form a single looping vesselRuns parallel, 1-8 cm from the intestinal wall

MEANDERING ARTERY OF RIOLANThe long vasa recta branches bifurcate and

anastomose at the antimesenteric border of the bowel after encircling it

The short ones, branches of the marginal artery, are responsible for the mesocolic 2/3rd of the colonic circumference

The vasa recta brevia run subserosally in the wall and penetrate the circular muscle and run in the submucosa

Effect of too much traction on an epiploic appendage resulting injury to one of the long branches of vasa recta followed by antimesenteric ischemia

ORIGIN AND ARTERIAL SUPPLY TO RECTUMUnpaired superior rectal artery

Right and left branchesMiddle rectal artery

Dosro-caudal area Inferior rectal artery

Ventral and medialMedial sacral artery

Posterior wall

VENOUS DRAINAGE OF THE COLON

VENOUS DRAINAGE OF THE RECTUMPortal systemSuperior rectal veinSystemic systemMiddle rectal vein Inferior rectal vein

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I.4a – Colon, Rectum, and Anus (Lecture)

Mainly responsible for the venous return of the distal 2 cm of the anal canal

Anastomoses occur between superior rectal vein (portal) and the middle and inferior rectal veins (systemic). These constitute a potential portosystemic shunt.

LYMPHATIC DRAINAGEEpicolic

Under the serosa of the wall of the intestineParacolic

On the marginal artery Intermediate

Along the large arteries (SMA and IMA)Principal

At the root of SMA and IMA

Above the pectinate line, drainage is to inferior mesenteric nodes

Below the line, drainage is to the inguinal nodes

INNERVATION Intramural plexus or intestinal enteric nervous systemMyenteric plexus

AuerbachSubmucosa plexus

Meissner Controls secretions

Table 1. Right vs Left ColonRIGHT COLON LEFT COLON

Sympathetic: lower 6 thoracic segments of the spinal cord

Sympathetic: L1, 2, 3 lumbar splanchnic nerves to the aortic plexus and the inferior mesenteric plexus

Parasympathetic: vagal fibers from the posterior trunk

Parasympathetic – pelvic splanchnic nerves S2, 3, 4

PHYSIOLOGYThe colon is a major site for water absorption and

electrolyte exchangeApproximately 90% of water contained in ileal fluid is

absorbed in the colon (1000 to 2000 ml/d), and up to 5000 ml of fluid can be absorbed daily

Sodium is absorbed actively via a Na-K ATPase channelChloride is absorbed actively via a chloride-bicarbonate

exchange

SHORT-CHAIN FATTY ACIDSShort-chain fatty acids are important sources of

energy for the colonic mucosa, and metabolism by colonocytes provides energy for processes such as active transport of sodium

Short-chain fatty acids (acetate, butyrate, and proprionate) are produced by bacterial fermentation of dietary carbohydrates

Lack of a dietary source for production of short-chain fatty acids, or diversion of the fecal stream by an ileostomy or colostomy, may result in mucosal atrophy and “diversion colitis”

MOTILITY – Cholinergic Response

Unlike the small intestine, the large intestine does NOT demonstrate migratory motor complex

Intermittent contractions of either low or high amplitudeLow-amplitude, short-duration contractions

occur in bursts and appear to move the colonic contents both antegrade and retrograde – absorption of water/electrolytes

High amplitude contractions create“mass movements”

DEFECATIONa complex, coordinated mechanism involving

colonic mass movement, increased intra-abdominal and rectal pressure, and relaxation of the pelvic floor

distention of rectum causes a reflex relaxation of the internal anal sphincter (the rectoanal inhibitory reflex)

this “sampling reflex” allows the sensory epithelium to distinguish solid stool from liquid stool and gas

if defecation does not occur, the rectum relaxes and the urge to defecated passes (the accommodation response)

defecation proceeds by coordination of increasing intra-abdominal pressure via the Valsalva Maneuver increased rectal contraction relaxation of the puborectalis muscle opening of the anal canal

CLINICAL EVALUATIONa complete history and PE is the starting point for

evaluating any patient with suspected disease of the colon and rectum

special attention should be paid to the patient’s past medical and surgical history to detect underlying conditions that might contribute to a gastrointestinal problem

if patients have had prior intestinal surgery, it is essential that one understands resultant gastrointestinal anatomy

in addition, family history of colorectal disease especially inflammatory bowel disease, polyps, and colorectal cancer, is crucial

medication use must be detailed as many drugs cause GI symptoms

before recommending operative intervention, the adequacy of medical treatment must be ascertained

in addition to examining the abdomen, visual inspection of the anus and perineum and careful digital rectal exam are essential

ENDOSCOPYAnoscopy

Useful instrument for examination of the anal canal Anoscopes are made in variety of sizes and measure

approximately 8cm in length A larger anoscope provides better exposure for anal

procedures such as rubber band ligation or sclerotherapy of haemorrhoids

Proctoscopy

IMAGING STUDIESPlain X-rays and Contrast StudiesComputed TomographyVirtual ColonoscopyMagnetic Resonance ImagingPositron Emission TomographyAngiographyEdorectal and Edoanal Ultrasound

PHYSIOLOGIC AND PELVIC FLOOR INVESTIGATIONSAnorectal physiologic testing uses a variety of

techniques to investigate the function of the pelvic floorThese techniques are useful in the evaluation of patients

with incontinence, constipation, rectal prolapse, obstructed defecation, and other disorders of the pelvic floor

ManometryNeurophysiologyRectal Evacuation Studies

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I.4a – Colon, Rectum, and Anus (Lecture)

MANOMETRYPerformed by placing a pressure-sensitive catheter in

the lower rectumCatheter is then withdrawn through the anal canal and

pressures recordedA balloon attached to the tip of the catheter also can be

used to test anorectal sensationThe resting pressure in the anal canal reflects the

function of the internal anal sphincter (Normal: 40-80 mmHg)

SQUEEZE PRESSURE Defined as the maximum voluntary contraction

pressure minus the resting pressure Reflects function of the external anal sphincter

(Normal: 40-80 mmHg ABOVE resting pressure)The high-pressure zone

Estimates the length of the anal canal (Normal: 2.0 – 4.0 cm)

The rectoanal inhibitory reflex Can be detected by inflating a balloon in the distal

rectum Absence of this reflex is characteristic of

HIRSCHSPRUNG’S DISEASE

NEUROPHYSIOLOGIC TESTINGAssesses function of the pudendal nerves and

recruitment of puborectalis muscle fibersPudendal nerve terminal motor latency measures the

speed of transmission of a nerve impulse through the distal pudendal nerve fibers (Normal: 1.8 – 2.2 msec)

Needle EMG has been used to map both the pudendal nerves and the anatomy of the internal and external sphincters

However, this examination is painful and poorly tolerated by most patients

Needle EMG has largely been replaced by pudendal nerve motor latency testing to assess pudendal nerve function and endoanal ultrasound to map the sphincters

RECTAL EVACUATION STUDIES Include the balloon expulsion test and video

defecographyBALLOON EXPULSION

Assess a patient’s ability to expel an intrarectal balloon

VIDEO DEFECOGRAPHY Provides a more detailed assessment of defecation Barium paste is placed in the rectum and defecation

is them recorded fluoroscopically Used to differentiate nonrelaxation of the

puborectalis, obstructed defecation, increased perineal descent, rectal prolapse and intussuception, rectocele, and enterocele

Addition of vaginal contrast and intraperitoneal contrast is useful in delineating complex disorders of the pelvic floor

LABORATORY STUDIESFecal Occult Blood TestingStool StudiesSerum TestsTumor MarkersGenetic Testing

FECAL OCCULT BLOOD TESTINGFOBT is used as a screening test for colonic neoplasms in

asymptomatic, average-risk individualsThe efficacy of this test is based upon serial testing

because the majority of the colorectal malignancies will bleed intermittently

Has been a nonspecific test for peroxidase contained in haemoglobin

STOOL STUDIESAre often helpful in evaluating the etiology of diarrheaWet-mount examination reveals the presence of faecal

leukocytes, which may suggest colonic inflammation or the presence of an invasive organism such as invasive E. coli or Shigella

Stool cultures can detect pathogenic bacteria, ova, and parasites

C. difficile colitis is diagnosed by detecting bacterial toxin in the stool

Steatorrhea may be diagnosed by adding Sudan red stain to a stool sample

SERUM TESTSSpecific laboratory tests that should be performed will be

dictated by the clinical scenarioPreoperative studies generally include CBC and

electrolyte panelThe addition of coagulation studies, liver function tests,

and blood typing/cross-matching depends upon the patient’s medical condition and the proposed surgical procedure

TUMOR MARKERSCarcinoembryonic antigen (CEA) may be elevated in 60-

90% of patients with colorectal cancerDespite this, CEA is NOT an effective screening tool for

this malignancyMany practitioners follow serial CEA levels after curative-

intent surgery in order to detect early recurrence of colorectal cancer

However, this tumor marker is nonspecific and no survival benefit has yet been proven

Other biochemical markers (ornithine decarboxylase, urokinase) have been proposed, but none has yet proven sensitive or specific for detection, staging, or predicting prognosis of colorectal CA

GENETIC TESTINGAlthough familial colorectal CA syndromes such as FAP

and HNPCC are rare, information about the specific genetic abnormalities underlying these disorders has led to significant interest in the role of genetic testing for colorectal CA

Tests for mutations in the APC gene responsible for FAP and in mismatch repair genes responsible for HNPCC, are commercially available and extremely accurate in families with known mutations

Although many of these mutations are also present in sporadic colorectal cancer, the accuracy of genetic testing in average individuals is considerably lower

These tests are not recommended for screening. Because of the potential psychosocial implications of genetic testing, it is strongly recommended that professional genetic counsellors be involved in the care of any patient considering these tests

NOTE: The following topics under Evaluation of Common Symptoms are not emphasized by Doc Mata but are still included in the ppt. Tinamad na ata siya gumawa ng ppt kasi sobrang copy-paste lang from Schwartz.

EVALUATION OF COMMON SYMPTOMSABDOMINAL PAIN

A nonspecific symptom with a myriad of causesPain related to colon and rectum can result from

obstruction (either inflammatory or neoplastic), inflammation, perforation or ischemia.

Plain X-rays and judicious use of contrast studies and/or a CT scan can often confirm the diagnosis

Gentle retrograde contrast studies (barium or Gastrografin enema) may be useful in delineating the degree of colonic obstruction

PELVIC PAINCan originate from the distal colon and rectum or from

adjacent urogenital structuresTenesmus may result from proctitis or from a rectal or

rectrorectal massCyclical pain associated with menses, esp when

accompanied by rectal bleeding suggests a diagnosis of endometriosis

PID also can produce significant abdominal and pelvic pain

The extension of a peridiverticular abscess or periappendiceal abscess into the pelvis may also cause pain

CT scan and/or MRI may be useful in differentiating these diseases

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I.4a – Colon, Rectum, and Anus (Lecture)

Proctoscopy (if tolerated) also can be helpfulOccasionally, laparoscopy will yield diagnosis

ANORECTAL PAINMost often secondary to an anal fissure or perirectal

abscess and/or fistulaPE can usually differentiate these conditionsOther less common causes:

Anal canal neoplasms Perianal skin infection Dermatologic conditions Proctalgiafugax–results from levator spasm and

may present without any other anorectal findingsPE is critical in evaluating patients with anorectal pain If a patient is too tender to examine in the office, an

examination under anesthesia is necessaryMRI may be helpful in select cases where the etiology of

pain is elusive

LOWER GI BLEEDINGThe first goal in evaluating and treating a patient with

GI haemorrhage is adequate resuscitationThe principles of ensuring a patient airway, supporting

ventilation, and optimizing hemodynamic parameters apply and coagulopathy and/or thrombocytopenia should be corrected

The second goal is to identify the source of haemorrhage

Because the most common source of GI haemorrhage is esophageal, gastric or duodenal, nasogastric aspiration should always be performed

Return of bile suggests that the source of bleeding is distal to the ligament of Treitz

If aspiration reveals blood or nonbile secretions, or if symptoms suggest an upper intestinal source, esophagogastroduodenoscopy is performed

Anoscopy and/or limited proctoscopy can identify hemorrhoidal bleeding

A technetium-99-tagged RBC scan is extremely sensitive and is able to detect as little as 0.1 ml/h of bleeding; however, localization is imprecise

If the technetium-99-tagged RBC scan is positive, angiography can then be employed to localised bleeding

Infusion of vasopressin or angioembolization may be therapeutic

Alternatively, a catheter can be left in the bleeding vessel to allow localization at the time of laparotomy

If the patient is hemodynamically stable, a rapid bowel perforation (over 4-6 hours) can be performed to allow colonoscopy

Colonoscopy may identify the cause of the bleeding, and cautery or injection of epinephrine into the bleeding site may be used to control haemorrhage

Colectomy may be required of bleeding persists despite these interventions

Intraoperative colonoscopy and/or enteroscopy may assist in localizing bleeding. If colectomy is required, a segmental resection is preferred if the bleeding source can be localized. "Blind" subtotal colectomy may very rarely be required in a patient who is hemodynamically unstable with ongoing colonic hemorrhage of an unknown source. In this setting, it is crucial to irrigate the rectum and examine the mucosa by proctoscopy to ensure that the source of bleeding is not distal to the resection margin

Occult blood loss from the GI tract may manifest as iron-deficiency anemia or may be detected with FOBT. Because colon neoplasms bleed intermittently and rarely present with rapid hemorrhage, the presence of occult fecal blood should always prompt a colonoscopy. Unexplained iron-deficiency anemia is also an indication for colonoscopy.

Hematochezia commonly is caused by hemorrhoids or fissure. Sharp, knife-like pain and bright-red rectal bleeding with bowel movements suggest the diagnosis of fissure.

CONSTIPATION AND OBSTRUCTED DEFECATIONConstipation has a myriad of causes:

Underlying metabolic

Pharmacologic Endocrine Psychologic Neurologic causes often contribute to the problem

A stricture or mass lesion should be excluded by colonoscopy or barium enema. After these causes have been excluded, evaluation focuses on differentiating slow-transit constipation from outlet obstruction. Transit studies, in which radiopaque markers are swallowed and then followed radiographically, are useful for diagnosing slow-transit constipation.

Anorectal manometry and EMG can detect nonrelaxation of the puborectalis, which contributes to outlet obstruction. The absence of an anorectal inhibitory reflex suggests Hirschsprung's disease and may prompt a rectal mucosal biopsy.

Defecography can identify rectal prolapse, intussusception, rectocele, or enterocele.

Medical management is the mainstay of therapy for constipation and includes fiber, increased fluid intake, and laxatives. Outlet obstruction from nonrelaxation of the puborectalis often responds to biofeedback.Surgery to correct rectocele and rectal prolapse has a variable effect on symptoms of constipation, but can be successful in selected patients.

Subtotal colectomy is considered only for patients with severe slow-transit constipation (colonic inertia) refractory to maximal medical interventions. Although this operation almost always increases bowel movement frequency, complaints of diarrhea, incontinence, and abdominal pain are not infrequent, and patients should be carefully selected

DIARRHEA AND IRRITABLE BOWEL SYNDROMEDiarrhea is also a common complaint and is usually a

self-limited symptom of infectious gastroenteritis. If diarrhea is chronic or is accompanied by bleeding or abdominal pain, further investigation is warranted

Irritable bowel syndrome is a particularly troubling constellation of symptoms consisting OF Crampy abdominal pain Bloating Constipation Urgent diarrhea

GENERAL SURGICAL CONSIDERATIONS Anterior ResectionHigh Anterior resection

Low Anterior ResectionExtended Low Anterior Resection

Hartmann’s Procedure and Mucus FistulaAbdominoperineal Resection

Extent of resection for carcinoma of the colon. A.Cecal cancer. B. Hepatic flexure cancer. C. Transverse colon cancer. D. Splenic flexure

cancer. E. Descending colon cancer. F. Sigmoid colon cancer

INFLAMMATORY BOWEL DISEASEULCERATIVE COLITIS

Rare in FilipinosCommon in Caucasians esp in Jews

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I.4a – Colon, Rectum, and Anus (Lecture)

Non-specific, idiopathic mucosal inflammation of the colon and rectum

Usually begins at the rectum moving proximally by direct extension (mucosa and submucosa)

Inflammation stops at the ileocolic junctionBloody mucoid diarrhea, abdominal pain, tenesmus,

fever

TREATMENTSulfasalazine – 4g/day relapse rate 9%/yrRowasa – topical enema of 5-ASASteroids, azathioprine, cyclosporine, mercaptopurine,

tacrolimusTotal abdominal colectomy with end ileostomy

CROHN’S DISEASENonspecific, transmural inflammationExacerbation/remissionMouth to anus, bloody diarrheaExtraintestinal manifestationSkip lesion, rectal sparing (40%)Terminal ileum and cecum (41%), SI (35%)Fistula, abscess, obstruction, stricture

NEOPLASMS OF THE LARGE INTESTINEPOLYP

A grape-like protrusion of tissue into the bowel lumen Sessile Pedunculated: flat on the mucosal surface Epithelial or submucosal: has a stalk Non-neoplastic Neoplastic

NON-NEOPLASTIC POLYPHyperplastic JuvenilePeutz-Jegher Syndrome

NEOPLASTIC POLYPTubular adenomaVillous adenomaTubulovillous adenoma

FAMILIAL ADENOMATOUS POLYPOSISa general neoplastic disorder of the intestineaffected area: mainly large bowelother: stomach, duodenum, small intestinemost important thing: colorectal CA develops before age

40 in nearly all untreated patients inherited as a Mendelian dominant. The gene

responsible (APC gene) has now been identified on the short arm of chromosome 5

Males and Females equally affected

CLINICAL FEATURESSYMPTOMATIC

PATIENTSASYMPTOMATIC

PATIENTS Loose stool Lower abdominal painWeight lossDiarrheaPassage of blood and

mucus

Usually are diagnose during screening or incidentally

Polyps are usually visible on sigmoidoscopy by the age of 15 years and will almost always be visible by age 30

Carcinoma of the large bowel occurs 10-20 years after the onset of polyposis

SOME EXTRA-INTESTINAL MANIFESTATIONSBENIGN MALIGNANT

Endocrine adenomaOsteomaEpidermoid cystHypertrophic retinal

pigmentationMedulloblastoma

Duodenal carcinomaDesmoid tumorBile duct, pancreatic CACA stomach

TREATMENT

Restorative proctocolectomy with an ileoanal anastomosisNowadays more frequently used Indicated esp in cases:

With serious rectal involvement with polyps Who are likely to be poor at attending for follow up With an established cancer of the rectum or sigmoid

Colectomy with ileorectal anastomosisWas practiced in the past as usual operation because it

avoids ileostomy in a young patient

CARCINOMA COLON

INCIDENCE OF CANCER-PhilippinesMALE FEMALE

1. Lungs2. Liver3. Colon/Rectum4. Stomach5. Prostate

1. Breast2. Cervix/Uterus3. Colon/Rectum4. Lungs5. Thyroid6. Ovary7. Liver

PREDISPOSING FACTORS Low-fibre containing dietSmoked fishHigh content of refined carbohydrate in dietRed meat Less intake of micronutrients esp Selenium

PATHOLOGYMicroscopically

Columnar cell CA originating in the colonic epithelium

Macroscopically Tumor may take one of four forms Type 1 – Annular Type 2 – Tubular Type 3 – Acinar Type 4 – Cauliflower (is the least malignant form)

Spreading Local Lymphatic Hematogenous

CLINICAL FEATURESCA of the LEFT side of the colon:

Pain Alteration of bowel habit Palpable lump Distension

CA of the SIGMOID Pain Tenesmus Bladder symptoms

CA of the CECUM and ASCENDING colon: Anemia Lump in the right iliac fossa Acute appendicitis Intermittent obstruction

May present with features of metastasis Palpable liver Jaundice Ascites

INVESTIGATIONSDiagnostics

Endoscopy Sigmoidoscopy Colonoscopy With tissue biopsy

Radiology Double contrast barium enema - Shows irregular

filling defect Ultra-sonography - Liver metastasis CT Scan - Local invasion esp in Pelvis

TREATMENTPreoperative preparation:

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I.4a – Colon, Rectum, and Anus (Lecture)

General: Correction of anemia by blood Correction of nutritional imbalance Correction of electrolyte imbalance Resuscitation if there is intestinal obstruction,

perforationSpecial preparation:

Dietary restriction to fluids for 2 days before operation

Laxative Enema Prophylactic antibiotics

Operation: Laparotomy is done The tumor is assessed for resectibility by checking

involvement ino Livero Peritoneumo Local lymph nodeso Tumor itself for Mobility

In cases of operable cases: Operations are done to remove the primary tumor

and the draining lymph nodes Removal of the portion of colon surrounding the

tumor depends on the side of the original tumor

CA PROCEDURE1. CA of the cecum/ascending colon

Right hemicolectomy

2. CA of the hepatic flexure

Resection will be extended correspondingly

3. CA of the transverse colon

Excision of the transverse colon and the 2 flexures together with the transverse mesocolon and the 2 flexures together with the transverse mesocolon and the greater omentum followed by end to end anastomosis

Alternative: extended right hemicolectomy

4. CA of the splenic flexure or descending colon

Resection from right colon to descending colon

Sometimes removal of colon up to the ileum with an ileorectal anastomosis

In cases of INoperable cases: Palliative procedure is done

LOCATION OF GROWTH PROCEDURE1. Upper part left colon Transverse colostomy2. Pelvic colonic growth Left iliac fossa colostomy3. Ascending colon growth

By-pass ilio-colic anastomosis

ANORECTAL DISEASESHaemorrhoids Ischiorectal abscessFistula in anoFissure in anoWartsFournier’s gangreneForeign body

HEMORRHOIDAL DISEASEPrimary Locations

3-7-11 o’clock positions Left Lateral – Right Anterior – Right Posterior

Submucosal cushion contains venules, arterioles, smooth muscle fibers

Part of continence mechanismExcessive straining, increase abdominal pressure, hard

stoolsBleeding, thrombosis, prolapseExternal haemorrhoids distal to dentate line Internal haemorrhoids proximal to dentate lineExternal Skin Tag

Redundant fibrotic skin at the anal verge due to previous thrombosed external haemorrhoid of past operation

GRADINGGRADE DESCRIPTION

1. FIRST DEGREE Bulge into anal canal, prolapse beyond dentate line

2. SECOND DEGREE Prolapse through anus, reduce spontaneously

3. THIRD DEGREE Require manual reduction4. FOURTH DEGREE Cannot be reduced prone

to strangulation

MANAGEMENTMEDICAL SURGICAL

DietSitz bathSuppositories

Excision:Milligan MorganRubber Band LigationHarmonic Scalpel

ANAL FISSUREEtiology:

Passage of large hard stool Conditions (Crohn’s disease, ulcerative colitis,

syphilis, TB, leukemia)Manifestations

Burning pain during and after bowel movement Bright red blood on toilet paper

Diagnosis Rectal examination / proctosigmoidoscopy

TREATMENTCONSERVATIVE SURGICAL

Anal hygience/bulk forming agents

Hot sitz bath Local anesthetic jellyBotolinum

Lateral internal sphincterotomy (chronic stage)

ANORECTAL ABSCESS5 potential spaces

Perianal space Ischiorectal space Intersphincteric space Deep posterior anal space

Etiology: Infection or anal gland Organism (fecal and cutaneous flora)

1. E. coli2. Bacteroides fragilis3. Staphylococcus4. Stretptococcus5. Clostridium sp.

Manifestation Pain in the anal region

Treatment Drainage/antibiotic Hygiene Hot sitz bath

TYPES OF ANORECTAL ABSCESS1. Perianal abscess2. Ischiorectal abscess

Diffuse swelling of ischio-rectal fossa3. Intersphincteric abscess

No apparent sign of swelling or induration in the perianal area

CLUE: deep seated tenderness when circumanal pressure is applied above the dentate line

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I.4a – Colon, Rectum, and Anus (Lecture)

Drainage: through the anal canal lining or through internal sphincteric muscle

4. Supralevator abscess Uncommon Mimic acute intra-abdominal condition Etiology: extension ofo Intersphincteric abscesso Ischiorectal abscesso Intra-abdominal abscess

NECROTIZING PERI-ANAL & PERINEAL INFECTIONEtiology:

Neglected or delayed treatment of primary anorectal infection

Extension of UTI particularly the periurethral glandManifestation

Pain, tenderness, and swelling with crepitation of perianal and scrotum or labia

Black spot on the site (necrosis)Treatment

Broad spectrum antibiotics Debridement Hyperalimentation/diverting colostomy and/or

cystostomy

FISTULA-IN-ANO Inflammatory tract with secondary opening (external)

and a primary opening (internal) in the anal canalEtiology:

Complication of perianal abscessClassification:

Inter-sphincteric Trans-sphincteric Supra-sphincteric Extra-sphincteric

Salmon Goodsalls Rule To locate the internal opening Anterior – straight tracts Posterior – curved tracts Exception: >3 cm curved

Manifestation: Previous history of perianal abscess Rule out ulcerative colitis and Crohn’s disease

(colonoscopy/barium enema)Treatment:

Identify the primary opening (probing/methylene blue/fistulography)

Fistulotomy/fistulectomy (healing by secondary intention)

If fistula is high in relation to anorectal ring, do a 2 stage procedure:1. Insert a seton wire or suture to the tract for

several weeks to create fibrosis2. Open the fibrous tract on the second stage after

6-8 weeks

-END-

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