Diagnosis and management of Benign Ano-colorectal conditions

1. • 32 YO male lorry driver presents with painful swelling at natal cleft
developed gradually over 4 days
• H/o similar swelling usually resolved with some discharges
• PMH – NIDDM
• O/e – Hirsute, BMI 29, 3x3 cm swelling with an opening oozing at the
top of natal cleft with some surrounding cellulitis
• Temp 37.5, pulse 90/min, BP 142/65 mmHg
What is your Diagnosis, Differential
Diagnoses and Management?

2. The diagnosis - Pilonidal abscess
• The differential diagnosis of pilonidal sinus disease
• A boil.
• Hidradenitis suppurativa.
• Ano-rectal fistula and fissure.
• Perirectal abscess.
Pilonidal sinus disease is a skin disorder usually found in the midline of
the natal cleft. A 'primary pit' or opening forms in the midline into
which loose hairs and debris enter to create an epithelial track (sinus)
which may become infected
Asymptomatic, or present acutely as a Pilonidal Abscess, or become a
chronically discharging Sinus/es ( midline/ lateral opening )

3. Pilonidal sinus
disease - an
acquired
condition.
A small midline pit develops at the site of a hair follicle. This sheds
its own hair and allows keratin and debris to fill it, facilitated by
the movement of the buttocks. The pit fills with debris -shed
squamous epithelium and foreign material. This is driven into the
depth of the pit causing a local inflammatory reaction, which
further elongates the pit.
A granuloma develops in the subcutaneous fat and over time,
further debris, hairs, and pus are forced into the midline pit and
build up under pressure to create an underlying cavity or track. An
abscess may form due to moist conditions in the natal cleft that
favour bacterial proliferation. A sinus (abnormal epithelialized
connection with the skin surface) may develop as infection
spreads, or as a result of rupture of an abscess.
A sinus may have one or more secondary openings lateral to the
primary pit, and if open, these may chronically discharge pus or
blood.

4. • Occurs on average 26 / 100,000 people
• Risk factors
• Male gender (3–4 times more likely than in women)
• Age 15–40 years
• Being white (more common than in black people,
due to different hair characteristics and growth patterns)
• Obesity, Hirsutism
• Deep natal cleft
• Lifestyle or occupation which involves sitting for
prolonged periods (more than 6 hours a day)
• Family history of pilonidal sinus disease
• Complications of pilonidal sinus disease
• Abscess, Cellulitis, Sepsis
• Chronic pain
• Altered body image and self-esteem
• Effects on personal relationships

5. Management
• Acute pilonidal abscess
• I&D ( day case under GA )
• FU in the Clinic
• Meticulous perianal hygiene with regular baths or showers.
• Buttock hair removal techniques, such as shaving, waxing, depilatory creams, or laser
treatment
• Discharging pilonidal sinus disease
• Colorectal referral
• Treatment of local infection/cellulitis ( Analgesia, Antibiotics, e.g., 7 days
course of Flucloxacillin 500 mg qid, plus Metronidazole 400mg tds )
• wide excision of the sinus tracks, followed by primary closure or leaving the
wound open to heal by secondary intention
• Bascom’s Procedure
• Karydakis Procedure
• Limberg technique with Rhomboid transposition flap, Z-plasty

6. Bascom Cleft
Lift Procedure

7. A folk tale from India
that teaches
intellectual awareness
by illustrating how
different perspectives
lead to distinct points
of view.
• translated to the
English language in the
19th century as a poem
by the English writer
John Godfrey Saxe. The
poem illustrates how
perception is based on
what a person is able to
see or touch
Six Blind Men and The Elephant

8. What is your Diagnosis and Management?
31 YO male presents to A&E with anal pain, fever and unwell
• 2 days h/o pain around anal area not responding to Analgesia
• Noticed today a painful swelling around anal area
• No previous similar history; fit, no PMH, no regular meds, smokes
• O/E – Temp 37.8 C, uncomfortable
• PRE – tender, swelling at 3 o’clock, mild inflammation around at the
anal margin
• DRE – not able to tolerate

9. Relevant Anatomy of the Anus/ Anal canal
Puborectalis

10. • Internal sphincter is composed of circular, non-striated involuntary smooth
muscle supplied by Autonomic Nerves System
• External sphincter is composed of striated voluntary muscle supplied by Pudendal
nerve
• Extension from longitudinal muscle layer support the sphincter complex
• The space bet sphincters – Intersphincteric plane
• Superior part of external sphincter fuses with Puborectalis muscle – maintaining
anorectal angle necessary for continence
• Lower part of the anal canal is lined by sensitive squamous epithelium
• BS – Superior, Middle and Inferior rectal (haemorrhoidal) vessels
• Lymphatic drainage - Inguinal and inf mesenteric chain/para-aortic nodes
• Anal glands in the submucosa and intersphincteric space at Dentate line are
considered the potential source of anal sepsis

11. A) Pelvi-rectal supra-levator space
B) Ischiorectal space
C) Perianal or superficial ischiorectal space
D) Marginal or mucocutaneous space
E) Submucous space
F) Anorectal intermuscular
(intersphincteric) space
1) Pelv-irectal supra-levator abscess
2) Submucous abscess
3) Ischiorectal abscess
4) Marginal abscess
5) Perianal abscess
6) Inter-sphincteric abscess

12. How should the patient be assessed?
• Full clinical history and Examination
 Duration
 Present of sepsis
 Associated GI symptoms; PRB, discharge (prev fistula), change of bowel habit
 GI history; diarrhoea, and pain, wt loss, F/H of IBD
 PMH; s/a DM, Malignancy, HIV, chemotherapy, prev organ transplant, recent
pelvic surgery
 Drug history; any immunosuppressant , steroids
• Examination – usually in left lateral position
 Swelling/abscess at anal verge, or minimal finding if deep sepsis
 DRE if possible; normally too much pain to tolerate
• Investigations
 FBC, U & E, CRP, Clotting

13. How should Anorectal sepsis be treated
• EUA, I(ncision) & D(rainage)
• Perianal and ischiorectal sepsis
- drain externally throu’ perianal skin
• Intersphincteric and suprasphincteric
abscesses s/b drained internally
• Management of associated fistulae ( e.g.,
loose draining seton insertion)
• Continued antibiotics if there is cellulitis/
immunocompromised patients (broad-
spectrum with anaerobic and G-ve cover)
• Consultation with Gastroenterologist in cases
of IBD/Crohn’s for treatment
• Usually FU 6-8 weeks
- A cruciate incision is made into abscess cavity
with excision of cruciate skin edges to deroof it
- Pus swab for M C&S
- Debridement of the abscess cavity, irrigated and
packed with Sorbsan/Aquacel ?

14. What is your Diagnosis and Management?
29 YO male referred to CR Clinic with 3 months h/o intermittent
discharge per rectum
• H/o a perianal abscess discharged spontaneously/ did not seek
medical advice
• Yellowish coloured discharged sometimes blood staining of his
underwear
• Otherwise well/ no change of bowel function, no PMH, Smoker
• O/E – G/C - NAD
• PRE – a small opening at 7 o’clock position with a palpable tract
• Proctoscopy reveals an internal opening in post midline, 4 cm from anal verge

15. Schematic anorectal clock

16. • A fistula – an abnormal communication between two epithelialized surfaces
• Perianal fistula – an inflammatory tract lined by granulation tissues between
anorectal canal and perianal skin
Types of Anal fistula (Park’s classification)
1. Intersphincteric
2. Trans-sphincteric
3. Suprasphincteric
4. Extrasphincteric
Idiopathic aetiology/ Cryptoglandular hypothesis – infection
begins at anal gland passing into Intersphincteric space, spread
via least resistant pathway – the resulting anorectal abscess,
then later a fistula develops
Other conditions; Crohn’s disease, TB, hidradenitis suppurativa,
HIV, foreign bodies, previous radiotherapy, trauma
Goodsall’s Rule
Internal opening at Dentate line

17. Investigation
• Proctosigmoidoscopy
• MRI - Gold standard – ability to demonstrate
secondary extensions
Coronal MRI (STIR Sequence) Primary
tract running up right Ischiorectal space
(short arrow) – crosses the sphincters to
open into anal canal
Blind Secondary tract (long arrow) at
contralateral side in the roof of left
ischiorectal fossa

18. • Eliminate the fistula
• Prevent recurrence
• Preserve sphincter function
Procedures
• Laying-open ( Fistulotomy )
• Seton insertion (loose, cutting, snug)
• Fibrin glue, plug
• LIFT ( Ligation of
Intersphincteric Fistula Tract )
• Advancement flaps
• VAAFT ( Video assisted anal
fistula treatment )
• FiLaC (Fistula tract laser closure)
• Defunctioning stomas
Treatment

19. What is your Diagnosis and Management?
33 YO male referred to CR Clinic with 8 weeks h/o bright red rectal
bleeding with bowel movement associated with pain and “stinging”
sensation for about an hour/few hours after
• H/o long-term constipation, otherwise fit and well, no change of
bowel function, no PMH
• GP consultation - ? Painful haemorrhoids; prescribed local agents
• O/E – G/C – NAD; Abd ex - NAD
• PRE – with difficulty – small posterior anal wound/ulcer noted
• DRE or Anoscopy NOT possible

20. Anal Fissure
• A tear in the lining of the mucosa of the anal canal
• 90% located in posterior midline – typically result from trauma from the hard
stool, also occurs from persistent diarrhoea; underlying hypertonicity (high
resting pressure) of Internal sphincter
• 10% anterior – birth trauma
• Sentinel pile – a skin tag
develops at the distal fissure
margin (painful haemorrhoid)
• Spasm of Internal sphincter
With bowel movement
- Causing pain and reduced
Blood flow in the area causing
Poor wound healing
Chronic Anal fissure > 8weeks

21. Management
• Normally no further investigation
• Conservative measures alone heals Anal fissure up to 80% ( +6 weeks)
• High-fibre diet with increased fluid intake
• Sitz baths
• Laxatives
• Medical treatment: Topical agent – GTN (Rectogesic 0.4%), Diltiazem 2%
• Facilitating local vasodilatation, relaxing sphincter, reducing anal pressure and
increasing BF; Twice daily up to 8 weeks, SE – significant headache (20-30%)
• BOTOX (Botulinum Toxin A) injection
• relaxes sphincter, and reducing resting anal tone
• Lasts for 2-3 months
• Heals chronic anal fissures up to 60 – 80 %
• Treatment can be repeated

22. Surgical operation for Anal fissure
Lateral internal sphincterotomy
• Open or close method – an incision over Intersphincteric
Groove at 3 or 9 o’clock, internal sphincter divided for
the length of fissure, not > ½ length of sphincter
• High success rate >90%; Low recurrence rate
• Important complication of Incontinence;
variable nature and severity up to 30%
Fissurectomy
Anal advancement flap
Anal dilatation (Lord’s procedure)
Nowadays no longer perform due to high
complication of anal incontinence

23. What is your Management?
47 YO male referred to CR Clinic with 3 months h/o intermittent bright
red rectal bleeding with bowel movement which is more regular
• Also notice something coming in/out with defecation, and
occasionally needs manual reduction
• H/o piles and had been treated with various topical and suppositories
with limited success until now
• Non-smoker, self-employed, fit and healthy
• O/E – G/C – NAD; Abd ex - NAD
• PRE – NAD
• Proctoscopy – 2nd and 3rd degree Haemorrhoids

24. Haemorrhoids
• Haemorrhoids are symptomatic Anal cushions
• Anal cushions – submucosal arterio-venous vascular plexuses maintaining anal
continence in Homo Sapiens Erectus
• Mainly at 3, 7 and 11 o’clock position
• Caused by
(Exact cause is unknown)
• Increased abd pressure ( excessive
straining, Obesity, Pregnancy, childbirth,
chronic cough)
• Constipation
• Genetics/ family tendency
• Ageing

25. Symptoms
• Bright-red painless bleeding
• Prolapse
• Mucous discharge
• Itchiness (pruritus ani)
• Pain (with complications/
external thrombosed haemorrhoid)
Classification
• First degree/Grade – bleed only
• Second degree – prolapse but reduce
spontaneously
• Third degree – prolapse and have to manually
reduce
• Fourth degree – prolapsed, irreducible

27. Management
• No further investigation unless haemorrhoids are a result of another d/s process, or
rectal bleeding may be attributable to other causes ( Red Flag Signs ) – Typically this
involves a flexible sigmoidoscopy or Colonoscopy
• Conservative
• Increase intake of fluid and fibres
• Avoid constipation and straining
• Stool softeners/ Laxatives
• Rubber Band Ligations ( treatment of choice for 2nd degree Haemorrhoids _
• Injection of Sclerosant ( Sclerotherapy – Phenol 5% in Almond oil )
• Surgical Operations
• Open (Milligan-Morgan)/ Closed (Furguson) Haemorrhoidectomy ( Ligation and
Excision )
• Stapled Haemorrhoidopexy
• HALO ( Haemorrhoidal Artery Ligation Operation ) or THD ( Transanal
Haemorrhoidal De-arterilization ) with suture mucopexy

28. Stapled
Haemorrhoido
-pexy
Excision and Ligation of
Haemorrhoids/ Open
technique
( Milligan Morgan )

29. What is your Diagnosis and Management?
71 YO female presented with 4 days h/o LIF pain
• It started as an ache – getting constant and worse; today feeling hot,
lethargic, anorexic and unwell; passing loose stool, no urinary
symptoms
• H/o similar episodes over a year, self-limiting, lasting few days
• PMH – hypertension, Type 2 DM on drugs
• O/E – G/C – Overweight/ flush; Temp 38.0 C, Pulse 115/min, BP
102/62 mmHg
• Abd – very tender LIF with mild guarding/ rest – soft with normal BS
• Bloods – Marked leucocytosis (WCC 21.5) with raised CRP (180)

30. Acute (Sigmoid) Diverticulitis
• Differential Diagnosis
• Left sided colitis
• Bowel cancer complication
• PID
• Ovarian pathology
• UTI/ Pyelonephritis
• Obstructive uropathy with urinary sepsis
• Management
• Sepsis Six
• Analgesia – usually of Opiates; avoid NSAIDs
• CT abd and pelvis with contrast – to confirm diagnosis

32. CT images of acute diverticulitis and (pericolic) diverticular abscesses
• Diagnosis of Acute Sigmoid diverticulitis with perforation resulting pericolic collection
• Hospital admission with continued IV Antibiotics ( Co-Amoxiclav 1.2 gm t.d.s )
• The collection ( pericolic abscess ) was drained percutaneously under radiological
guidance( CT-guided drainage )
• Patient was discharged Day 4 with oral antibiotics
• Review at Ambulatory Care on D7, repeated CT, resolution of the collection and
removal of drain
• FU Colorectal clinic 10 -12 weeks

33. What is Diverticular disease?
• Consists of
• Diverticulosis – colonic outpouching
• Diverticulitis ( simple or complicated )
• Diverticular bleeding
• Prevalence in left colon (95%)
Around 75% of > 70 YO in
Western world
• Involvement of Sigmoid alone is
65%; entire colon – 7%
• 75% of Diverticulosis remains
asymptomatic
25% become symptomatic –
pain, distension, altered bowel
habit, diverticulitis and
other complications
Diverticula usually occur
adjacent to the vasa recta, the
small vessels that extend into
the submucosa, the weakest
areas of the colonic wall, usually
occur on the mesenteric side of
the colon.

34. • Diverticulitis is caused by mechanical obstruction of a (thin-walled)
diverticulum compromising BS and render it to bacterial invasion/
infection and inflammation ( Simple Acute Diverticulitis )
• Complicated Diverticulitis - It can lead to perforation into the wall
( intramural abscess ), pericolic fat and mesentery ( pericolic
abscess), or peritoneal cavity ( localised or generalised peritonitis )
• When inflammation and infection settle – fistula formation
(colovesical, colovaginal, enterocolic, colocutaneous) occurs in 5% of
cases
• Healing and later fibrosis can cause stenosis of colon, or adhesion
causing SBO
• Bleeding: most common cause of Massive LGI bleeding ( 30-50% of
cases ). The bleeding stops spontaneously in most cases (70 -80%)

35. • What causing Diverticular disease ( Aetiology )?
• Refined Western diet low in dietary fibre
• Altered collagen structure with aging
• Disordered motility and increased luminal pressure especially in narrow
sigmoid colon
• The risks of diverticular complications
• Red meat and high-fat diet
• Smoking ( but not Caffeine and Alcohol )
• Obesity
• Lack of exercise
• NSAIDs – usage increase risk of perforation
• Diverticular disease is rare in Africa and Asia where the diet is high in
natural fibre

36. Management
Asymptomatic diverculosis
• Advise to high fibre diet containing whole grains, fruits and vegetables, increased
gradually ( to minimize flatulence and bloating) and should be maintained for life
• Adequate fluid intake
• Most people with diverticulosis will remain asymptomatic, and no follow up or treatment
is necessary
Mild, uncomplicated diverticulitis can be managed at home
• Prescribe broad-spectrum antibiotics to cover anaerobes and Gram-negative rods:
• Suitable choices include co-amoxiclav or a combination of ciprofloxacin and
metronidazole (if the person is allergic to penicillin ) for a week
• Prescribe paracetamol for pain.
• Recommend clear liquids only. Gradually reintroduce solid food as symptoms improve
over 2–3 days.
• Review within 48 hours, or sooner if symptoms deteriorate. Arrange admission if
symptoms persist or deteriorate.

37. Surgical Management
• Indications for Emergency Surgery
• Purulent or faecal peritonitis (perforation)
• Uncontrolled sepsis or failure to improve with conservative management
• Laparotomy and Washout
• Usually Hartmann’s procedure (Sigmoid resection with formation of end colostomy
and closure of rectal stump)
• Resection and primary anastomosis (+ Defunctioning ileostomy)
• Mortality about 15% up to 50% in Faecal Peritonitis
• Laparoscopy and Washout
• Elective Sigmoid Resection
• Younger patients
• Less perform nowadays

39. Toxic Megacolon ( Acute Toxic Colitis )
• Toxic colitis with segmental or generalised dilatation of colon
• Acute presentation with significant morbidity and mortality form
inflammatory or infectious colitis
• Diagnostic criteria
• Radiological evidence of acute colitis
• Any 3 of following – Fever > 38.6℃ , Tachycardia >120/min, WCC > 10.5, or
anaemia
• Any one of following – Dehydration, Altered mental status, Electrolyte
abnormality, or Hypotension
• Involvement of a Multidisciplinary team ( gastroenterologist, surgeon,
critical care, anaesthetist )
• Operative treatment ( perforation, massive rectal bleeding, or lack of
improvement after appropriate medical therapy for 72 hours )

40. Case history
• #1 - A 30 YO man with a history of ulcerative colitis (UC) presents with
severe abdominal pain and distention. He is currently being treated
for an acute colitis flare characterised by 20 bloody bowel movements
daily, fevers to 38.9°C (102°F), and left upper quadrant pain. P/E
reveals tachycardia and hypotension. Abd examination shows
distention with signs of focal peritonitis in the left lower quadrant
• #2 - A 60 YO woman presents to the A&E department with a 4-day
history of watery diarrhoea, fevers, and worsening abdominal pain.
Her significant PMH includes sinusitis, for which she has been taking
antibiotics for the past 3 weeks. On P/E, she is tachycardic and febrile,
and her abdominal examination reveals diffuse abdominal tenderness
and distention

41. Step-by-step Diagnostic approach, initial Treatment, and Investigations
• H/o ongoing episodes of colitis symptoms associated with colitis ( diarrhoea –
watery/bloody, fever, chills, crampy abd pain )
• h/o IBD, recent use of Abs and other medications s/a Opiates, anticholenergics,
antidepressants, chemotherapy, steroids, or antimotility agents
• P/E – Vital signs ( HR, BP, Temp, GCS, Urine OP )
• Abd – distention, decreased BS, tenderness, signs of peritonitis ( focal/local or
diffuse )
• Atypical presentations ( no clear h/o e.g., C.Diff colitis no recent AB use/ no
diarrhoea )
• Laboratory - FBC with differential, U&E, Serum Lactate, BC, Stool samples
• Imaging – CT – AP – mandatory test in assessment of severity, CXR, AXR
• Sigmoidoscopy and biopsy – in selective patients – to identify e.g., pseudomembranous
colitis, IDB, or identify full-thickness necrosis
Contraindicated in presence of peritonitis

42. Test Result
FBC Raised WCC with left shift (Neutropenia in immunocompromised or severe
sepsis)
Low Hb abd reduced Hct
Serum electrolytes Hypokalaemia, Hypomagnesia, deranged Renal functions
Serum Albumin, CRP Hypoalbuminaemia, elevated CRP
Serum Lactate May be elevated
Stool studies ( for C&S, ova and
parasite assay including C. Diff -
NAAT (Nucleic acid amplification test)
May be positive for infectious organism
CT-AP Diffuse colonic wall thickening, submucosal oedema, pericolic fat stranding,
colonic dilatation, absence of normal haustral marking
CXR Free air under diaphragm indicates perforation
AXR Massive dilated colon ( Colonic dilatation of >6cm in presence of systemic
sepsis is suspicious of Toxic megacolon )
BC ( on admission and prn ) May be positive for pathogens

43. First choice – Vancomycin 500mg qid
Second choice – Metronidazole 500 mg
IVI tds + Vancomycin 500mg Enema
Total colectomy with end-ileostomy
• IV Ciclosporin and Infliximab have been utilised as Rescue Therapy when Corticosteroids fail to resolve
severe colitis associated with IBD
• Faecal microbial transplantation - a proven safe and effective treatment of recurrent or refractory
Clostridium difficile colitis

44. A 22-year-old man presented with abdominal pain,
passage of blood and mucus per rectum, abdominal
distention, fever, and disorientation. Findings from
sigmoidoscopy confirmed ulcerative colitis. Abdominal
radiographs obtained 2 days apart show mucosal oedema
and worsening of the distention in the transverse colon.
The patient's clinical condition deteriorated over the next
36 hours despite steroid and antibiotic therapy, and the
patient had to undergo a total colectomy and ileostomy
The entire colon is
distended, measuring up
to 9 cm at the transverse
colon and cecum with
bowel wall oedema and
surrounding fat stranding

45. What is your Diagnosis and Management?
72 YO female presented with 6-8 hrs h/o sudden onset severe, constant
central abd pain which has been getting progressively worse
• Feeling unwell, vomited several times
• PMH – hypertension on ACEI, OA on opiates, ex- smokers 20 cigarettes/day
for last 40 years
• O/E – looks pale and unwell, irregular pulse 100/min, BP 104/62 mmHg, O2
Sat 94% on air, resp rate 26/min
• Abd – very tender generally with no signs of guarding or peritonism,
reduced BS
• Bloods – Leucocytosis (WCC 16.5) , Lactate 5.5 mmol/L, Serum Amylase
267

46. Differential diagnosis
• High index of suspicion for bowel ischaemia ( Acute mesenteric ischaemia )
• Any causes of acute abdomen – Acute pancreatitis, cholecystitis, diverticulitis,
perforated viscus
What are the appropriate investigations?
• ECG
• CT-AP with contrast – Radiological features of intestinal ischaemia ( thickened
bowel wall, mural haematoma and gas, mesenteric vessel congestion, gas in the
mesenteric or portal system (late signs)
• Unclear diagnosis – CT Angiogram or Selective Angiography
If CT imaging or angiography is not immediately available , urgent
exploratory laparotomy is indicated in patients with suspected ischaemic
bowel

47. CT –angiogram showed thromoembolus within
proximal SMA
- Underwent emergency laparotomy and
thrombolectomy
- the bowel was mostly viable, only requiring
localized resection of non-viable SB with
primary anastomosis.

48. Intestinal ischaemia can be classified into three broadly defined types:
• Acute mesenteric ischaemia
• Superior mesenteric artery embolus
• Superior mesenteric artery thrombosis
• Non-occlusive mesenteric ischaemia
• Superior mesenteric vein thrombosis
• Focal segmental ischaemia
• Chronic mesenteric ischaemia
• Colonic ischaemia
• Reversible ischaemic colonopathy
• Transient ulcerating ischaemic colitis
• Chronic ulcerating ischaemic colitis
• Colonic gangrene
• Fulminant universal ischaemic colitis.

49. Comparison of
symptoms/signs
and investigations
for the three
types of
ischaemic bowel
disease

50. A large thrombus (blue arrow) is seen filing the right sided
branches of the superior mesenteric vein. The bowel drained
by these occluded branches is thick-walled and poorly
enhancing (blue dotted line).
Branches draining the more proximal small bowel remain
patent (green arrow) and jejunal loops appear to have
normal wall thickness (greed dotted line)
''Thumb-printing' is a radiologic sign indicating
bowel-wall thickening due to oedema that is
often a finding in patients with mesenteric
ischemia

51. References
• Bailey & Love’s Short Practice of Surgery, 27th Edition ( Norman Williams )
• Oxford Case Histories in General Surgery, 2018
• A Companion to Specialist Surgical Practice, Colorectal Surgery, Sixth Edition
• Medscape (https://www.medscape.com/generalsurgery)
• BMJ Best Practice (https://bestpractice.bmj.com/)
• Radiopedia (https://radiopaedia.org/?lang=us)
• Various Sources ( World Wide Web/ Internet )