Common Problems

Question 1

Constipation causes

Answer 1

IBS
Idiopathic slow transit
Pelvic flow dyssynergia
Intestinal obstr- colon cancer
Intestinal pseudo-obstr
Painful anal conditions- fistula,
Drugs: opiates, Al antacids, antimuscarinics( ACh in M3 recept) 
Hypothyroidism (bowel no energy to peristalsis)
Hypercalcaemia (work too much wrongly?)
Spinal cord lesion (affecting S2-S4-> autonomic parasymp) 
Depression( ⬇️Dopamine and 5HT3)
Immobility 
Hirschsprung's disease

Question 2

What happens in constipation?

Answer 2

Common
Dietary advice and ressuarance
Esp in elderly, assc w/ immobility + poor diet
Women: assc w/ slow transit or postpartum pelvic floor abnormalitites.

IBS
Colorectal cancer always excluded in middle- aged and elderly ppl.

Mx
High fibre diet and bulging agents = 1st line
Severe cases Only: long-term laxative e.g. MgSO4.

Question 3

Faecal incontinence

Answer 3

Recurrent uncontrolled passage of faecal material.
Faecal impaction common cause in elderly.
Anal sphincter tear or trauma to pudental nerve after childbirth or anal surgery eg for haemorrhoids.
Impaired anal sensation: Diabetes, MS, dementia and spinal cord injuries.
Hx and O/E ! + DRE will exclude most causes.

Invx

1. Sigmoidoscopy- exclude mucosal disease,
2. Imaging of anal sphincters by anal endosonography or MRI
3. Anorectal manometry (to asses anal sphincter pressure)
4. Rectal Sensory testing- by ballon distention tomasses rectal sensation and compliance.

Tx- cause.

Question 4

Fx affecting continence

Answer 4

Mental function
Stool vol
Consistency of stool
Structural and fx integrity of anal sphincters
Puborectalis m,
Pudental nerve fx
Rectal distentibility + anorectal sensation

Question 4

Megacolon

Answer 4

Number of conditions in which colon is dilated.
Commonest cause: chronic constipation,
Other: Chaga’s disease + Hirschsprung’s D
Tx: w/ laxatives altho Hirschprung’s D responds to surgical resection.

Question 5

Whats Hirschsprung’s D?

Answer 5

Congenital aganglionic segment in rectum.

Question 6

Ischaemic Colitis

Answer 6

Older groups
Abdo pain+ rectal bleed + smts shock.
Sigmoidoscopy often normal apart some blood.
Tx- sx altho surgery may be required for gangrene, perforation or stricture formation.

Question 7

Whatbare strictures?

Answer 7

Narrowing of a section of the intestine for example, causing an obstruction or slowing food passage.

Can also form w/ recurrent inflammation.

Question 8

Whats a fistula?

Answer 8

Abnormal passage between hollow/ tubular organ and body surface or between two hollow organs.
Anal fistula:
Channel formed at anal canal and the anal skin- hole.
2 buttholes.

An abcess can form in the fistula :(

Question 9

Colon polyps

Answer 9

Polyp- elevation above mucosal surface
May be single or multiple
Usually asx
70% are adenomas.
Colonic polyps classified as neoplastic (Adenomas and carcomas)
Non neoplastic, or hamartomatous.
Non neoplastic- hypeplastic polyps composed of normal cellurar stuff w/o dysplesia or malignancy potential.
May be indistinguishable from adenomas at endoscopy.
Inflamatory polyps are also non neoplastic- occur on backround of IBD and represent healinh regenerating mucosa.

Question 10

Harmartomatous polyps

Answer 10

Benign tumours- overgrowth of mature cells. 2 types:
Juvenile polyps- dominantly inherited , occuring in kids and teenagers- present early w/ diarrhoea, bleeding or intussusception.

Peutz- Jeghers polyps.

Question 11

Adenomatous polyps

Answer 11

Tumours of benign neoplastic epithelium.
Common, 10% of population.
Asx, altho big ones can bleed and cause aneamia.
Vilous adenomas- diarrhoea and hypokalaemia (not absorbed!!??)

Adenamtous polyps- carry malignant risk ‼️ that ⬆️ w/ polyp size.
Removed in endoscopy !

Question 12

Familial Adenomatous Polyposis (FAP)

Answer 12

Autosomal Dominant –> develop hundrets of adenomatous polyps throughout GI tract at eaely stage—> colon cancer unless large bowel is removed.

FAP- germline mutations from APC gene (adenomatous polyposis coli) on chromosome 5.
Gene testing offered to unaffected family members .

Genetic councselling + offered prophylactic colectomy early in adulthood.
After colectomy, risk of small b cancer, esp duodenum–> surveillance gastroscopy recommended.

Question 13

What facilitates screening in young patients with FAP?

Answer 13

The fact that these pts have congenital hypertrophy of the retinal pugment epithelium (CHRPE)
So this + genetic testing.