MRCS module (question)

Discussion in 'MRCS Forum' started by david ne', May 9, 2004.

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  1. david ne'

    david ne' Guest

    SELECT MODULE

    1. RECTAL BLEEDING AND ALTERED BOWEL HABIT


    1. INTRODUCTION:

    RECTAL BLEEDING IS COMMON.IT CAN BE CAUSED BY A VARIETY OF CONDITIONS.FRESH RECTAL BLEEDING SHOULD BE DISTINGUISHED FROM MELAENA,THE PASSAGE OF ALTERED BLOOD:AS THE LATTER INDICATES BLEEDING FROM THE UPPER GIT.

    CHANGE OF BOWEL HABIT IS ANOTHER IMPORTANT SYMPTOM.IT MAY OR MAYNOT BE ASSOCIATED WITH RECTAL BLEEDING.THE BOWEL HABIT IS VERY VARIABLE. THE NORMAL PATTERN FOR AN INDIVIDUAL MUST BE ESTABLISHED BEFORE ANY CONCLUSIONS CAN BE DRAWN.


    2. AIMS:

    AFTER WORKING THROUGH THIS MODULE YOU SHOULD BE ABLE TO :

    A.EVALUATE FROM CLINICAL PRESENTATION THE LIKELY CAUSES OF RECTAL BLEEDING AND CHANGE OF BOWEL HABIT

    B.UNDERSTAND THE UNDERLYING PATHOPHYSIOLOGY OF THE COMMON CAUSATIVE CONDITIONS

    C.DEVELOP AN APPROPRIATE SYATEM FOR HISTAORY TAKING AND EXAMINATION

    D.ORGANIZE APPROPRIATE INVESTIGATIONS

    E.APPLY PRINCIPLES OF MANAGEMENTFOR THE COMMON CONDITIONS



    3.EXAMPLES IN PRACTICE:

    THESE EXAMPLES SHOW RECTAL BLEEDING AND ALTERED BOWEL HABIT IN PRACTICE. THINK ABOUT THE KEY ISSUES RELEVANT TO EACH. YOU WILL BE ASKED TO THINK ABOUT THE DIFFERENTIAL DIAGNOSES LATER. AS YOU WORK THROUGH THIS MODULE YOU WILL BE REMINDED OF THE APPROPRIATE CASES.


    CASE 1. Mr. J.S. (PAINLESS ANAL CANAL BLEEDING)

    AN OTHERWISE HEALTHY 35 YEAR OLD MALE HAS PASSED FRESH BLOOD SEVERAL TIMES OVER THE PAST FEW MONTHS.THIS OCCURS IMMEDIATELY AFTER OPENING HIS BOWELS ,WITH BLOOD DRIPPING INTO THE TOILET PAN.THERE IS NO PAIN.THERE HAS BEEN NO CHANGE IN BOWEL HABIT.


    KEY ISSUES:

    A.OBTAIN A CLEAR HISTORY

    B.ABDOMINAL EXAMINATION IN ALL CASES

    C.RECTAL EXAMINATION

    D.PROCTOSCOPY AND SIGMOIDOSCOPY

    E.CONSIDER FURTHER INVESTIGATIONS

    F.CONSIDER IMMEDIATE TREATMENT, IF APPROPRIATE

    G.CONSIDER SURGERY , IF APPROPRIATE.



    CASE 2: Mrs.P.S. (PAINFUL ANAL CANAL BLEEDING)

    THIS 30 YEAR OLD FEMALE HAD A BABY SIX MONTHS AGO.SINCE THEN SHE HA EXPERIENCED PAIN AND BRIGHT RED RECTAL BLEEDING EVERY TIME HER BOWELS MOVE.


    KEY ISSUES:

    A.TAKE A CLEAR HISTORY OF BLEEDING PATTERN AND OBSTETRIC HISTORY

    B.CAREFULLY INSPECT ANAL CANAL,PRIOR TO DIGITAL EXAMINATION

    C.DIGITAL RECTAL EXAMINATION AND ENDOSCOPY ONLY IF ACHIEVALBLE WITHOUT PAIN

    D.CONSIDER CONSERVATIVE OR MEDICAL TREATMENT

    E.CONSIDER EXAMINATION UNDER ANAESTHETIC AND APPROPRIATE SURGICAL TREATMENT


    CASE3: Mr.F.W. (PERIANAL PAIN AND BLEEDING)

    ABOUT 6 MONTHS AGO,THIS 35 YEAR OLD MALE HAD AN EPISODE OF SEVERE PERIANAL PAIN.HE WAS ADMITTED TO HOSPITAL FOUR DAYS LATER.BY THAT TIME ,THE PAIN HAD RESOLVED AFTER COPIOUS DISCHARGE AND BLEEDING.HE HAD AN OPERATION TO "CLEAN THINGS UP".HE HAS SINCE SUFFERED FROM INTERMITTENT PERIANAL DISCHARGEAND OCCASIONAL BLEEDING.HE ALSO HAS PRURITIS ANI.


    KEY ISSUES:

    A.OBTAIN CLEAR HISTORY,PREFERABLY FROM CASE NOTES

    B.CAREFUL EXTERNAL EXAMINATION OF PERIANAL REGION

    C.CAREFUL DIGITAL EXAMINATION OF ANAL CANAL

    D.CONSIDER EUA AND SURGICAL TREATMENT


    CASE 4: Mrs. E. J. (RECTAL PROLAPSE)

    THIS 72 YEAR OLD FEMALE HAS NOTICED PROTRUSION OF THE RECTUM EVERY TIME HER BOWELS MOVE.SHE HAS TO REPLACE IT MANUALLY.OCCASIONALLY THE RECTUM PROTRUDES SPONTANEOUSLY.SHE CAN BE INCONTINENT OF FAECES WHEN THIS HAPPENS.


    KEY ISSUES:

    A.CAREFUL EXTERNAL EXAMINATION OF ANAL CANAL:LOOK FOR A GAPING ORIFICE

    B.DIGITAL EXAMINATION TO ASSESS SPHINCTER TONE

    C.EXAMINATION WHILE PATIENT IS STRAINING AS AT STOOL



    CASE 5: Mr.B.W. (BLEEDING WITH CHANGE OF BOWEL HABIT)

    THIS 70 YEAR OLD MAN HAS NOTICED DARK BLOOD IN HIS STOOLFOR THE PAST 6 MONTHS.HE HAS ALSO NOTED VAGUE LOWER ABDOMINAL PAIN,WITH ALTERNATING CONSTIPATION AND LOOSE STOOL.IN THE PAST MONTH HE HAS LOST HALF A STONE IN WEIGHT.HIS MOTHER HAD A COLOSTOMYFOR MANY YEARS.HIS BROTHER HAS JUST HAD A BOWEL OPERATION.


    KEY ISSUES:

    A.CAREFUL HISTORY OF THE SYMPTOMS AND ELUCIDATION OF FAMILY HISTORY

    B.CAREFUL ABDOMINAL EXAMINATION WITH PARTICULAR REFERENCE TO LIVER

    C.RECTAL EXAMINATION,PROCTOSCOPY AND SIGMOIDOSCOPY

    D.CONSIDER FURTHER INVESTIGATIONS



    CASE 6: Miss. H.D. (BLOODY DIARRHOEA)

    THIS 25 YEAR OLD FEMALE HAS HAD WATERY BLOOD STAINED DIARRHOEA AND CRAMPING ABDOMINAL PAIN FOR 6 WEEKS.SHE HAS LOST HALF A STONE IN WEIGHT AND HAS DEVELOPED PAIN IN SEVERAL JOINTS.


    KEY ISSUES:

    A.CAREFUL HISTORY

    B.CAREFUL ABDOMINAL EXAMINATION WITH SPECIAL REGARD TO ABDOMINAL TENDERNESS AND SIGNS OF PERITONITIS

    C.RECTAL EXAMINATION AND SIGMOIDOSCOPY

    D.CONSIDER FURTHER INVESTIGATION



    CASE 7: Mr. R.K. (MASSIVE RECTAL BLEEDING)

    THIS 60 YEAR OLD MAN IS BROUGHT INTO THE A AND E DEPARTMENT.HE IS PASSING LARGE QUANTITIES OF FRESH BLOOD PER RECTUM .THERE IS NO OTHER HISTORY. HE IS PALE SWEATY AND DROWSY.


    KEY ISSUES:


    A.ASSESS VITAL SIGNS AND CONSCIOUSNESS LEVEL

    B.RESUSCITATION

    C.RAPID LOCALISATION OF BLEEDING POINT

    D.PROMPT THERAPEUTIC INTERVENTION


    CASE 8: Mrs.S.H. (MELAENA)

    THIS 45 YEAR OLD FEMALE HAS BEEN PASSING JET BLACK LIQUID MOTION FOR 48 HOURS.SHE IS FEELING DIZZY AND SHORT OF BREATH.FOR SEVERAL MONTHS SHE HAS HAD INTERMITTENT EPIGASTRIC PAIN.


    KEY ISSUES:

    A.ASSESS VITAL SIGNS

    B.CONTINUE MONITORING AND CHECK HEMOGLOBIN

    C.RESUSCITATION, IF NECESSARY

    C.PROMPT INVESTIGATION (ENDOSCOPY)

    D.INITIATE TREATMENT
  2. david ne'

    david ne' Guest

    rest of them

    4.WHAT YOU SHOULD THINK ABOUT



    4.1. PATHOPHYSIOLOGY


    PATHOPHYSIOLOGICAL MECHANISMS THAT MAY LEAD TO RECTAL BLEEDING AND CHANGE OF BOWEL HABIT CAN BE GROUPED INTO FOUR BROAD CATEGORIES:



    A.NEOPLASIA

    B.INFLAMMATION

    C.ISCHEMIA

    D.DEGENERATION/IDIOPATHIC





    4.1.1 NEOPLASIA


    NEOPLASIA CAN BE CLASSIFIED AS FOLLOWS:


    A.RECTAL POLYP OR CARCINOMA

    B.COLONIC POLYP OR CARCINOMA

    C.VASCULAR TUMOR

    D.ANAL CANCER


    ADENOMAS OR ADENOMATOUS POLYPS AND ADENOCARCINOMAS ARE THE COMMONEST FORMS OF NEOPLASIA OF THE COLON AND RECTUM.ADENOMATOUS POLYPS MAY BE PEDUNCULATED OR SESSILE:HISTOLOGICALLY THEY MAY BE PREDOMINANTLY TUBULAR OR VILOUS.VILLOUS ADENOMAS ARE MORE PRONE TO MALIGNANT CHANGE THAN TUBULAR ADENOMAS,AND THEY OFTEN PRODUCE LARGE AMOUNTS OF MUCUS.ADENOMAS UNDER 1 CM IN DIAMETER RARELY CONTAIN INVASIVE CARCINOMA,WHEREAS THIS IS COMMON IN POLYPS OVER 2 CM.


    CARCINOMAS CAN BE POLYPOID,ULCERATED OR STENOTIC-DEPENDING ON THEIR SIZE.THEY ARE COMMONEST IN THE RECTUM(35%) FOLLOWED BY THE SIGMOID COLON(26%).APPROXIMATELY 70%OF TUMORS ARE FOUND IN THESE SITES:THE REMAINING 30% ARE DISTRIBUTED ROUGHLY EQUALLY AROUND THE REST OF THE COLON( 22% IN ASCENDING COLON,12%IN TRANSVERSE COLON AND 5%IN DESCENDING COLON).

    IT IS BELIEVED THAT MOST, IF NOT ALL , CARCINOMAS ARISE FROM PRE EXISTING POLYPS AND THAT THIS PROGRESSION IS DUE TO THE ACCUMULATION OF MUTATIONS IN PROTO-ONCOGENES AND TUMOR SUPPRESSOR GENES.




    ???? WHY ARE CANCERS THOUGHT TO ARISE FROM POLYPS.....
    ANS. POLYPS AND CANCERS OFTEN CO EXIST
    LARGE POLYPS ARE LIKELY TO CONTAIN INVASIVE CANCER
    THE DISTRIBUTION OF CANCER AND POLYPS IS SIMILAR
    FAP LEADS INEVITABLY TO CANCER.




    ABOUT 1 % OF ALL COLORECTAL CANCERS ARISE IN PTS. WITH FAP.THIS DOMINANTLY INHERITED CONDITION IS CHARACTERIZED BY THE APPEARANCE OF MULTIPLE POLYPS IN THE COLON(USUALLY IN THE LATE TEENS OR EARLY TWENTIES).IF LEFT UNTREATED, THIS INEVITABLY LEADS TO THE DEVELOPMENT OF INVASIVE CA.THIS CONDITION IS DUE TO A GERMLINE MUTATION OF THE APC GENE.OF COLORECTAL CANCERS,5%ARISE IN PTS WITH ANOTHER DOMINANTLY INHERITED CONDITION-HNPCC.THIS IS DUE TO GERMLINE MUTATION IN DNA MISMATCH REPAIR GENES.



    IN SPONTANEOUS COLORECTAL CANCER,THE AETIOLOGICAL FACTORS ARE UNCLEAR BUT DIET PLAYS AN IMP. ROLE.ESPECIALLY A HIGH INTAKE OF ANIMAL FATS APPEARS TO BE A RISK FACTOR.




    TYPICAL SERIES OF GENENTIC MUTATIONS IN THE DEVELOPMENT OF A SPORADIC COLORECTAL CANCER....
    NORMAL--------- DYSPLASIA APC
    DYSPLASIA----- SMALL POLYP K- RAS
    SMALL POLYP---- LARGE POLYP DCC
    LARGE POLYP ---- CANCER P53




    POLYPS AND CANCERS ARE FRIABLE AND CONTAIN LARGE FRIABLE VESSELS WHICH TEND TO BLEED EASILY.AS THIS WILL TEND TO OCCUR WITH THE PASSAGE OF STOOLSPAST THE LESION,THE BLEEDING USUALLY PRESENTS AS BLOOD ON THE SURFACE OF THE STOOL OR MIXED IN WITH THE STOOL.



    THE PATTERN OF BLEEDING WILL ALSO DEPEND ON THE SITE OF THE TUMOR.

    1.RECTAL CANCER WILL TEND TO PRESNET PREDOMINANTLY WITH BLEEDING AN DOFTEN WITH TENESMUS

    2.CANCER IN THE LEFT SIDE OF THE COLON WILL TEND TO PRESENT WITH A COMBINATION OF DARK RED BLEEDING AND CHANGE OF BOWEL HABIT

    3.RT.SIDED CANCER TENDS NOT TO PRESENT WITH OVERT BLEEDING OR CHANGE OF BOWEL HABIT BUT RATHER WITH ANEMIA.

    4.RARELY,VASCULAR TUMORS EG.HEMANGIOMAS MAY CAUSE BLEEDING ESP FROM THE SMALL BOWEL.

    5.ANAL CANCER MAY ALSO BLEED :ANAL DISCOMFORT IS OFTEN PRESENT.




    ?????? WHY SHOULD COLORECTAL CANCER PRESENT IN DIFFERENT WAYS ACCORDING TO ANATOMICAL SITE.

    ANS. 1.RECTAL CANCERS ARE MORE LIKELY TO CAUSE FRESH BLEEDING OWING TO THEIR PROXIMITY TO THE ANAL CANAL.TENESMUS IS CAUSED BY THE RECTAL SENSATION OF A FILLING DEFECT.

    2.LF. SIDED COLONIC CANCERS ARE LIKELY TO CAUSE OBSTRUCTIVE SYMPTOMS BECAUSE OF A COMBIANTION OF A NARROW LUMEN AND SOILD FAECES.
    3.RT. SIDED CANCERS TEND NOT TO CAUSE OBSTRUCTIVE SYMPTOMS.THE RIGHT SIDE OF THE COLON IS DISTENSIBLE AND FAECES ARE LIQUID
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