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Important Points in a Constipation History
- Definition - compared to the patient's normal
- Is it long standing - why present now?
- any associated symptoms - pain, tenesmus etc.
Important Points in a Diarrhoea History
- Definition - is it the consistency or the number of motions
- Long standing - why now?
- Travel History
- Food History
Examination of patient with altered bowel habit
- Examine for systemic disease - Thyroid status and neuromuscular disorders
- Abdominal exam - masses, faecal loading and peritonitis
- Check hernial orifices
- PR - haemorrhoids, fissures and rectal masses
Investigations of Constipation
- Bloods: - TFTs
- - Calcium
- - Routine bloods
- Imaging: - AXR - faecal loading, obstruction - Sigmoidoscopy - mass, faecal loading
- Other: - Colonic transit study
Investigations of Diarrhoea
- Routine Bloods
- AXR - Colitis, massScope - visualise mucosa
- Anti alpha-gliadin antibodies
Differential Diagnosis of Constipation
- Functional: - Low fibre diet
- - Sedentary lifestyle
- - Irritable bowel syndrome
- Systemic: - Drugs - e.g. opiates
- - Neuromuscular disorders
- - Metabolic disorders - e.g. thyroid
- Colonic causes: - Colorectal Ca.
- - Diverticular Disease
- - Obstruction
- Anal causes: - Fissures
- - Haemorrhoids
Differential Diagnosis of Diarrhoea
- Infection: - bacteria
- - viral
- - amoebic dysentery
- Travelers' diarrhoeaDrugs: - Antibiotics
- - Laxatives
- Small Bowel Disease: - Crohn's
- - Coeliac
- - Blind loop syndrome
- Large Bowel Diease:
- - UC
- - Colorectal Ca.
- - IBS
- - Spurious
PR bleeding in younger patients
- Anal fissures
- Commonly benign in younger years, no surgical treatment needed.
PR bleeding in older population
- Diverticular Disease
- Colorectal Cancer
Investigation of PR bleeding
- Rule out Upper GI bleeding in massive haemorrhage - OGD
- Faecal occult blood
- Urgent Colonoscopy
- Visceral angiography
Classification of Polyps
- - Adenoma:
- - Tubular
- - Tubullovillous
- - Villous
- Non-neoplastic: - Hamartoma
- - Inflammatory
Presentation of Colonic Polyps
- Polyps are usually asymptomatic and devoid of signs
- With multiple lesions bleeding may be obvious
- Diagnosis is normally through screening or incidentally in investigation of unexplained iron deficiency anaemia.
- Rare clinical syndrome where villous adenoma causes loss of K+ rich mucosa and causes hyperkalaemia.
Investigation of Polyps
- When a polyp is found, full examination of the large bowel and rectum should be undertaken.
- Biopsies should be taken of all areas of concern for pathological opinion.
Treatment of an adenomatous polyp
- Finding of any polyps, especially those >1cm require:
- - Complete examination of the bowel under colonoscopy
- - Removal of all discovered lesions - usually endoscopically
- - Regular life-long surveillance for recurrence and/or the development of Bowel Ca.
Follow up in patients with polyps
Familial Adenomatous Polyposis
- Autosomal Dominant Condition
- Caused by mutations in APC gene
- Polyps first appear between 13 and 30.
- FAP is associated with non-colonic manifestations:
- - Desmoid Tumours
- - CHRPE
- - Fibromas*
- - Osteomas*
- - Sebaceous cysts*
- * + FAP = Gardner's Syndrome
- Total colectomy before 25yo is normal, with ileo-anal pouch formation.
Hereditary Non-Polyposis Colon Cancer
- Autosomal Dominant Condition
- High risk of many abdominal cancers
- Caused by mutations in mismatch repair genes
- Stratify risk of cancer using Amsterdam Criteria
- Less polyps than FAP but more malignant condition
Presentation of Right-sided colon tumours
- Non-specific symptoms of malaise, weight loss and vague abdominal pain
- Self-detected abdominal mass
- Iron deficiency anaemia
- Rarely, intestinal obstruction.
Presentation of Left-sided colon tumours
- More likely to cause an obstructed picture
- Colicky abdominal pain
- altered bowel habit
- PR mucus
- 10% present with visible PR blood
- effects of local spread:
- - Faecal incontinence - anal sphincters
- - Back pain - sacral plexus
- - UTI - retrovesical fistula
- - Renal Failure - infiltration of ureters
Risk Factors for Colon Cancer
- Dietary Factors:
- - Bile salt conversion to carcinogens
- - Low intake of fibre = slow transit
- Adenomatous polyps
- - FAP
- - HNPCC
- Inflammatory Bowel Disease:
- - Ulcerative Colitis
- - Crohn's Disease
- Alcohol and Tobacco
Routes of Metastasis in Colorectal Cancer
- Local Invasion:
- - Sacral plexus
- - Ureters
- - Bladder / uterus+cervix
- - Paracolic nodes
- - para-aortic nodes
- - Liver first then.....
- - Lung, kidney and bone
- - Ascites
- - Ovaries
Investigations of Colorectal Cancer
- PR EXAM - must be done to confirm presence of blood and to check for rectal masses
- Sigmoidoscopy - flexible sigmoidoscopy can get as far as splenic flexure
- Colonoscopy - Full length colon examination is required even in the presence of a distal lesion.
- Barium Enema - Traditional method of investigation colon
- CT pneumocolon (virtual colonoscopy) - Can also check for mets
- PETCT / MRI - used pre-op
Staging Colorectal Cancer
- Duke Classification is commonly used
- - A - Cancer confined to the mucosa - 90% 5yr-survival
- - B - Tumour extends through full thickness of wall. Nodal involvement and mets absent - 75% 5yr-survival
- - C1 - Local lymph nodes involved - 50% 5yr-survival
- - C2 - More proximal lymph nodes involved - <50% 5yr-survival
- - D - Not in official classification, but denotes metastatic disease - 6% 5yr-survival
Treating Colonic Cancer
- Dukes A-C colon cancer is primarily treated by surgical removal.
- B and C tumours also receive adjuvant therapy.
- Right-sided tumours are removed via a right hemicolectomy.
- Left-sided tumours are removed by a resection tailored to the segment of bowel involved.
Treating Rectal Cancer
- Patients with locally advanced disease may receive pre-op chemo/radiotherapy to shrink the tumour
- This reduces the risk of 'margin positive' resections and consequently, local recurrence
- Rectal techniques:
- - Anterior resection - used in lesions of the upper 2/3 of rectum
- - Abdominoperineal (AP) excision - used in lower 1/3 rectal tumours
- - Hartmann's procedure - emergency procedure where anastomosis is not readily available, leaving rectal stump.
Oncological Treatment of Colorectal Cancer
- Radiotherapy: - can be used alone in small lesions
- - used after local excision
- - after margin positive resection
- - palliation
- - After resection
- - FOLFOX / FOLFIRI
- - Cetuximab - used for liver metastases