GI + Colorectal 2 Flashcards
What are diverticula
Diverticula are small, bulging pouches that can form in the lining of your digestive system
Occur due to hypertrophy of the muscle propria, with diverticula then occurring at sites of potential weakness in the bowel wall (entry points of blood vessels)
This creates a ‘true’ diverticulum of just mucosa, without the muscular covering (as opposed to Meckel’s)
What is diverticulosis?
The presence of diverticula
What is diverticulitis?
The inflammation of diverticula
What is diverticular disease?
Symptomatic diverticula
Where are diverticula commonly found?
In the sigmoid, with 95% of the complications arising at this site
What are the causes of diverticula?
Low fibre diet (hard stools and thus higher pressure needed to move them)
Rarer associations: Marfans, Ehler’s Danlos syndrome and PKD
What are the clinical features of diverticular disease?
Mimic carcinoma of the colon:
Left sided colic, relieved by defecation
Altered bowel habit - including blood and mucus passage
Nausea
Flatulence
Severe pain and constipation if severe (causing lumina narrowing)
What investigations should be done for diverticular disease?
PR - may reveal pelvic abscess or colorectal cancer - main ddx
Sigmoidoscopy / Colonoscopy
Barium enema
CT
what is the management of diverticular disease?
Mebeverine = 1st kline medical management
What are the clinical features of Diverticulitis (infection)
Infection due to stagnation of the contents of teh diverticula
Severe left sided colic
Constipation (or overflow diarrhoea)
Symptoms mimicking appendicitis but on the left
What are the signs of diverticulitis?
Fever + tachycardia
Tenderness, guarding and rigidity on the left hand side
Can be a palpable mass in the LIF
Raised WCC and inflammatory markers
What is the management of diverticulitis?
Mild Attacks - low grade fever:
Bowel rest (fluids only) at home
Oral co-amoxiclav +/- metronidazole
Severe attacks (complicated - high grade fever)
Admit if pain cannot be controlled, or oral fluids not tolerated
Give analgesia, IV fluids, IV cefuroxime and metronidazole and keep NBM
Order erect CXR, AXR and contrast CT to assess for complications
DO not scope in acute attack
What complications can arise from diverticulitis?
Perforation Bleeding Stricutre Abscess Fistula
What does perforation lead to following diverticulitis?
Formation of paracolic or pelvic abscess, fistulae or generalised peritonitis
Presents with ileus +/- shock
Mortality = up to 40%
Management is with laparotomy +/- Hartman’s procedure
What is the presentation and management of abscess formation following diverticular disease?
Swinging fever, leucocytosis and localising signs (e.g. a boggy rectal mass)
Should be drained under CT guidance
How does bleeding following diverticular disease present?
Sudden, painless bleeding and also chronic occult loss, as a result of erosion of vessels at the fundus of the diverticulum
Large volumes can be lost, requiring transfusion
These often stop with bed rest
If they do not stop, locate the bleeding point via angiography (or colonoscopy) and then treat with embolisation (surgery rare)
Adrenaline injections and diathermy may negate the need for surgery
What kind of fistulas can form following diverticular disease?
Colovesical - leading to UTI and pneumaturia
Colovaginal - leading to foul discharge
Where does intestinal obstruction most commonly occur following diverticular disease?
Most commonly in the sigmoid after repeated episodes of diverticulitis
Chronic inflammation leads to scarring and the formation of a diverticular mass, which causes obstruction and may mimic colonic carcinoma
What is the management of asymptomatic diverticula of the colon?
Dietary advice is required for asymptomatic diverticulae
Increase unprocessed food intake and dietary fibre intake as part of a balanced diet (>20g/day of insoluble fibre)
What is the management in patients with uncomplicated by symptomatic diverticula disease?
Mebeverine first line
If there is very severe or recurrent diverticulitis, surgery may be considered
Rarely resorted to, complication rates are high
What are the indications for surgery in diverticular disease?
Small confined pericolonic abscess rarely require surgery
Any generalised peritonitis will require surgery
Emergency colonic resection required in massive haemorrhage / perforation
What are the risk factors of colorectal carcinoma?
Family history (+FAP/HNPCC) Age Western diet - low in fibre, high in fats - exercise, obesity UC (Chron's if it is in the colon) Smoking
POLYPS
What are the protective factors against colorectal carcinoma?
Fruit and vegetables / fibre consumption
Exercise
HRT
Aspirin / NSAIDs
Which gene is related to colorectal cancer?
Hereditary non-polyposis colorectal cancer (HNPCC) is responsible for <5% = arises from germline mutations in mismatch repair genes
Familial adenomatous polyposis (FAP) is responsible for <1% cancers, and occurs due to tumour suppressor gene APC mutations
Describe the morphology of colorectal cancer
Mostly adenocarcinoma with characteristic ‘signet ring’ cells on histology
What % of colorectal cancers occur in which section?
Caecum and ascending colon: 15% Transverse colon: 10% Descending colon: 5% Sigmoid colon: 25% Rectum 45%
What is the initial appearance of colorectal cancer? How does it invade?
Usually appear as a polypod mass with ulceration, spreading initially by direct infiltration through the bowel wall
Then involves the lymphatics and blood vessels, metastasising primarily to the liver
Transcoelemic spread can also occur
How is cancer staged?
TNM
Used to be dukes
A - tumours invade submucosa +/- muscularis propria (confined to lining of bowel)
B - tumours invade past the muscularis propria (into subserosa/directly into other organ, no nodal involvement) (through wall of bowel
C - Regional lymph node involvement
D - distant mets
Describe the stages of TNM staging
T = tumour (TX - cannot be evaluated)
T1: the tumour is in the submucosa
T2: tumour has grown into muscularis propria
T3: Tumour in subserosa
T4: The tumour has grown into the surface of the visceral peritoneum - all layers
N = nodes
N1a there are tumour cells in 1 regional node N1b (2-3)
N2a: tumour cells in 4-6 LN
2b: 7+ regional LN
M0 = no mets
M1a: one other part of body
1b: more than 1 other part of the body
1c: cancer spread to peritoneal surface
Describe the grading of tumours in colorectal cancer
GX: cannot be identified
G1: the cells are more like healthy cells (well differentiated)
G2: the cells are somewhat like healthy cells - moderately differentiated
G3: the cells look less like healthy cells (poorly differentiated)
G4: The cells barely look like healthy cells (undifferentiated)
What kind of cancers are Anal cancers?
Mainly SCC
What are the risk factors for anal cancer?
Anoreceptive sex
Syphilis infection
Anal warts/cervical caner - HPV
immunosuppression
What is the pectinate line?
An embryological division between the upper 2/3 and the lower 1/3 of the anal canal
Describe the epithelium above the pectinate line
Columnar epithelium, lymph drainage to internal iliac nodes and portal venous drainage, thus hepatic metastasis
Describe the epithelium below the pectinate line
Squamous epithelium, lymph drainage to the superficial inguinal nodes, and caval venous drainage, thus pulmonary metastases
More common in men, better prognosis
What are the presentation of a colorectal tumour?
Abdominal mass, abdominal pain, haemorrhage, perforation or fistula
How do right sided tumours tend to present? (CAECUM)
Often asymptomatic and may present with IDA/weight loss
Anaemia Obstruction (ileocaecal: SBO - bilious/faeculant) Mass dyspepsia, pain - colicky Appendicitis
How do left sided tumours tend to present? (RECTAL)
PR blood/mucus, altered bowel habit tenesmus obstruction - large bowel Pain - lower bladder sx ?
mass on PR examination
What is the presentation of anal tumours?
bleeding, pain, changes in bowel habit, pruritus ani, masses or stricture
What are the indications for 2ww referral in patients >40
Rectal bleeding or change in bowel habit for >6w
Persistent rectal bleeding, in those over 45, with no obvious evidence of benign anal disease
IDA Hb <10g/dl without an obvious cause
Palpable abdominal / PR mass
What Ix are done for patients with suspected colorectal carcinoma?
FBC (microcytic anaemia), LFTs (metastatic indicator) FIT
Colonoscopy (gold standard, as allows biopsy (polypectomy)
non-contrastCT chest, abdo, pelvis (staging)
Carcino-embryonic antigen (CEA) can be used to monitor disease
MRI (rectal cancer)
?Chest mets: CT CAP
Double contrast: barium and air - cancer appears like an apple core
Describe the surgical procedures for colorectal cancer?
Wide resection of the growth and regional lymphatics Right hemicolectomy left hemicolectomy sigmoid colectomy anterior resection abdomino-perineal resection Hartmann's procedure - resection of rectosigmoid colon with closure of the anorectal stump and formation of an end colostomy Endoscopic stenting
What are the indications for a right hemicolectomy?
For caecal, ascending and proximal transverse colon tumours
may be temporary end ileostomy prior to ileo-colic anastomoses
What are the indications for a a left hemicolectomy?
For distal transverse or descending colon tumours
may be temporary end colostomy prior to coli-colic anastomoses
What are the indications for a sigmoid colectomy
high anterior resection
for sigmoid tumours
What are the indications for an anterior resection?
For low sigmoid/high rectal tumours
colorectal anstamosis achieved at first operation, although this may be covered by a temporary loop ileostomy
What are the indications for an andomino-perineal resection
for tumours low in the rectum
permanent colostomy with removal of rectum and anus
no anastomosis
What are the indications for a Hartmann’s procedure?
For bowel obstruction or palliation
Resection of recto-sigmoid colon, with temporary end colostomy and closure of the rectal stump
What is the indication for endoscopic stenting?
Palliative
How is radiotherapy used to manage colorectal cancers?
Used pre-operatively in rectal cancer to reduce recurrence and increase survival
Higher risks of post-operative complications (DVT, pathological fractures, fistula formation)
Post-operative radiotherapy is only used if high risk of local recurrence
How is chemotherapy used to manage colorectal cancers?
Adjuvant 5-FU (and folic acid) can reduce mortality of higher stage tumours
May be used in palliation of metastatic disease
What is the treatment of anal carcinoma?
Radiotherapy plus chemotherapy (5-FU and mitomycin/cisplatin)
75% retain normal anal function
What are the requirements for patients having surgery for CRC?
Colonoscopy before or soon after to look for additional lessons as 5% of tumours are metachronous
How should patients having surgery for CRC be followed up?
Stage II/III disease should have serum CEA every 3 months and colonoscopy every 3 years
NHS bowel screening programme offers screening to all men/women aged 60-69 via Faecal immunochemical Test (FIT) sampling every 2 years
Colonoscopy is used in those most at risk due to personal history, family history, adenoma or IBD
What is the manamgent of an obstructing colon cancer?
A-E: IV fluids to replace losses, catheter for fluid balance.
Bloods for amylase, FBC and U+E
Analgesia and NG tube decompression
AXR and erect CXR - confirm diagnosis and check for perforation
CT to determine level of obstruction
Gastrograffin follow through studies can also show the level of obstruction, and also have some therapeutic effects on mild mechanical obstruction
Definitive surgery is the management once the patient is adequately hydrated (or endoscopic stenting for palliation)
What are the symptoms of a patient with a small/large bowel obstruction?
Vomiting: Undigested food suggests gastric outlet obstruction Bilous vomiting suggests upper SBO faeculent vomiting (thicker/foul smelling) suggests more distal SBO
Pain: colicky abdominal pain in early obstruction, pain may be absent in long standing obstruction
Constipation: may not be absolute in proximal obstruction
What are the signs of a patient with a small/large bowel obstruction?
Distention
Tinkling bowel sounds
dehydration
central resonance to percussion, dull flanks
Scars: previous surgery causing adhesions
Palpable mass (causing the obstruction
No abdominal tenderness (unless strangulation)
What are the common causes of small bowel obstruction?
Adhesions (80%)
Hernias
Chron’s disease
Intussusception
What are the common causes of large bowel obstruction?
Carcinoma of the colon
Diverticular disease
Sigmoid volvulus
Constipation
What are the complications of bowel obstruction?
Bowel becomes oedematous and distends
bacteria proliferate in the obstructed bowel
As the bowel distends, vessels become stretched and the blood supply is compromised, leading to strangulation (ischaemia and necrosis)
Eventually, bowel will perforate
Symptoms develop more gradually in large bowel obstruction - due to the capacity
What investigations are appropriate in a patient with suspected obstruction?
FBC U+E amylase, LFTs
ABG
Urinalysis
Supine AXR: distended proximal bowel, absent gas distally
Erect CXR: fluid levels in SBO, air under diaphragm if perforation
Contrast enema: Differentiates obstruction and pseudo-obstruction, can identify the level of obstruction and ileo-caecal competency
Gastrogaffin
CT can indicate level of obstruction but cannot always give the diagnosis
What is paralytic ileus?
Temporary disruption of normal peristaltic activity without mechanical blockage
No bowel sounds
What are the causes of paralytic ileus?
Post surgery (normal up to 4 days)
Due to anastomotic leak (intra-abdominal sepsis)
Electrolyte disturbances
Critically unwell patients on ITU with multiple injuries
How is paralytic ileus managed?
Still carries the same risk of third space losses: treated with NG and NBM.
Must remain vigilant in monitoring as may silently develop into a mechanical ileus caused by adhesions and thus it is important to remain vigilant in monitoring
How do you differentiate SBO and paralytic ileus?
Bowel sounds: Present in SBO, absent in paralytic ileus
AXR: air in the colon in paralytic ileus, none in SBO
Diffuse air-fluid levels in paralytic ileus
What is pseudo-obstruction?
the name for large bowel obstruction when no identifiable cause can be found (form of paralytic ileus)
When does strangulation occur?
Most commonly occurs with volvulus or hernia
Can occur in any obstruction
What are the differentiating features of strangulation?
Increasing pain/tenderness with leucocytosis and systemic upset
May progress to peritonism with absent bowel sounds
What is volvulus?
A twisting loop of bowel around its mesenteric axis, resulting in obstruction together with venous occlusion at the base of the mesentery
Who gets sigmoid volvulus?
Most common in elderly, constipated patients
What is the AXR appearance of sigmoid volvulus?
Coffee been appearance
What is the management of sigmoid volvulus?
Insertion of a long flatus tube advanced into the sigmoid, which often untwists the volvulus (releases large amounts of liquid faeces/gas)
If this is unsuccessful, there will be an emergency laparotomy
What is a caecal volvulus?
Due to congenital malrotation, and gives the classic ‘embryo’ appearance of an ectopically placed caecum on an AXR
Treatment is untwisting at laparotomy
SBO vs LBO vomiting
bilious in SBO
Absent/faeculant in LBP
SBO vs LBO constipation
May not be absolute in SBO
Absolute in LBO
SBO vs LBO Progression
More rapid in SBO than LBO
What is the management of a patient with SBO?
ABCDE resuscitation
Drip and suck:
NBM + NG decompression of the stomach (Ryle’s tube)
If no signs of strangulation, delay operative management by 48 hours
(50% SBO due to adhesions will resolve with conservative management after 4 days)
If signs of strangulation or severe obstruction then the patient will be taken to theatre, and the aetiology of the obstruction dealt with surgically
Antibiotic therapy will also be commenced if there are signs of strangulation
What is the management of LBO?
Generally requires operative management (Hartmann’s)
If due to faecal impaction, enemas or manual evacuation will be tried
What is intussusception?
Telescoping of the bowel
What is the presentation of intussusception?
Intermittent colic, red-currant jelly PR bleeding and a sausage shaped mass in the upper abdomen
What is the USS sign of intussusception?
Target sign
What is the treatment of intussusception?
Air insufflation
What are the causes of intestinal obstruction in children?
Intussusception
Incarcerated hernia
Malrotation of the bowel with midgut Volvulus - presents as obstruction with PR blood/mucous + abnormal bowel position on AXR
Hirschprung’s disease
Meconium ileus
What are the factors causing constipation?
General: poor diet, dehydration, lack of exercise, IBS, old age, pain
Anorectal disease: fissure, stricture, rectal prolapse
Metabolic/endocrine: hypercalcaemia, hypothyroid, hypokalaemia
Drugs: Opiates, anticholinergics, iron, aluminium based antacids, diuretics
Neuromuscular: spinal/pelvic nerve injury, diabetic neuropathy, hirschprung’s disease
What investigations are done in constipation?
Bloods: FBC, ESR, U+Es, Calcium, TFTs and endoscopy
Where does the anal canal run from and to?
Superior aspect of the pelvic diaphragm to the anus and is normally collapsed
What is the internal anal sphincter?
Involuntary sphincter surrounding the upper 2/3 of the anal canal
How does the anal sphincter maintain faecal continence
Tonic contraction is stimulated by sympathetic fibres from the superior rectal/hypogastric plexus
Parasympathetic fibres inhibit this tonic contraction, thus requiring contraction of puborectalis / the external anal sphincter to maintain continence
What is the external anal sphincter?
Surrounds the Lower 2/3 of the anal canal and is under voluntary control, mediated by the inferior recall nerve
What are the anal cushions?
Highly vascular areas, formed of smooth muscle with sub epithelial anastomoses of the rectal arteries/veins
The anal cushions contribute to the continence along with the anal sphincter, and are at 3, 7 and 11 o clock when viewed from the lithotomy position (legs up in surgery)
What are haemorrhoids?
Prolapses of these cushions, containing the normally dilated rectal venous plexus covered by rectal mucosa
Arise due to a breakdown of the smooth muscle layer, the muscularis mucosae
What are the factors predisposing to haemorrhoids?
Mainly idiopathic
Increased anal tone (chronic constipation)
Factors that cause congestion of superior rectal veins (cardiac failure, pregnancy, rectal carcinoma, any raised IAP)
Where does the superior rectal vein drain into?
The inferior mesenteric vein (portal) whereas the middle/inferior rectal vein drain cavally
Essentially, the anastomoses of the anal cushions are porto-canal anastomoses, so in portal hypertension, they may become varicose to give ano-rectal varices (can co-exist with haemorrhoids in patients with portal hypertension)
Describe the classification of haemorrhoids?
1st degree: confined to the anal canal: bleed but do not prolapse
2nd degree: prolapse on defecation, then reduce spontaneously
3rd degree: prolapse outside the anal margin on defecation, but may be manually reduced
4th degree: remain prolapsed outside the anal margin at all times
What are the symptoms of haemorrhoids?
Rectal bleeding: bright red blood on paper Prolapse Mucous discharge Pruritus ani Pain if the piles become thrombosed
What are the complications of haemorrhoids?
Anaemia - if severe/continued bleeding
Thrombosis
How does thrombosis of piles occur?
If prolapsing piles are gripped by the anal sphincter (strangulated piles), then venous return is occluded, leading to thrombosis
The haemorrhoids swell, become purple and tenderness, causing significant pain/distress
The thrombosed piles often fibres within 2-3 weeks, giving spontaneous cure
Management is conservative, with cold compress, opioids and rest
How should a patient with ?haemorrhoids be examined?
Abdo exam: palpable masses, enlarged liver
Rectal exam: prolapsing piles are obvious
Proctoscopy/rigid sigmoidoscopy: can visualise the piles, and assess for a lesion higher in the rectum
Colonoscopy / Flexi-sigmoidoscopy: if symptoms suggest a more sinister pathology
What are the differential diagnoses of rectal bleeding?
Haemorrhoids
Anal fissure: very tender, skin tag
Diverticulitis: bloody ‘splash’ in pan, LIF symptoms
Rectal cancer (tenesmus, PR bleeding with defecation)
Colon cancer (red blood mixed with the stool, change in bowel habit)
UC: abdominal pain, urgency)
Chron’s disease: weight loss, chronic diarrhoeah
Massive upper GI bleed: melena, but frank blood if very large, usually haematemesis also
Trauma
Ischaemic / infective colitis
Angiodysplasia
How are haemorrhoids managed?
Advice: plenty of fluid and not to strain
Topical analgesia/astringents and bulk forming laxative: anusol
Sclerotherapy
Banding
Surgery
What is sclerotherapy/how is it done?
5% phenol in almond oil injected above each pile as a sclerosing injection
Suitable for first and second degree piles
Painless as placed high in the canal, above the dentate line
One or more repeat injections may be needed at monthly intervals
What is banding and how is it done?
Application of a small rubber band to the protruding mucosa
This leads to strangulation
Can be applied to first to third degree piles
Care may be taken to position the band above the dentate line
What are the indications for surgery in piles?
Third and fourth degree piles
stapled haemorrhoidectomy or haemorrrhoidal artery ligation are the main methods used (haemorrhoidectomy now less common)
What is a perianal haematoma?
Thrombosed external pile
however, unlike internal haemorrhoids, it is covered by squamous epithelium supplied by somatic nerves and thus is painful
What is the presentation of a perianal haematoma?
acute, sudden pain and lump at the anal verge
OE, lump is tense, smooth, dark blue and cherry sized
Untreated, either subsides over a few days to leave a fibrous tag or rupture to discharge clotted blood
How is a perianal haematoma managed?
Incised and drained under local anaesthetic
If they are already discharging or being resorbed when seen, hot baths and reassurance is all that is necessary
What are the anal sinuses/crypts?
Small recesses that act to release mucous when compressed by faeces, to aid the evacuation of the anal canal
these crypts are the most common sites of infection, but these can spread to various sites
Perianal infections most commonly affect anon-receptive males, presenting with a visibly red, exquisitely tender swelling next to the anus
What are the different types of perianal infections?
Anorectal abscesses
Pilonidal sinus
Perianal warts
What Is the cause of an anorectal abscess?
Usually caused by gut organisms
Associated with Chron’s, DM and malignancy
45% are perianal with 30% ischiorectal, 20% intersphincteric and 5% supralevator
What is the treatment of an anorectal abscess?
Incision and drainage under GA, to prevent rupture / possible formation of fistula
What is the cause of a pilonidal sinus?
Obstruction of natal cleft hair follicles around 6cm above the anus, with ingrowing of hair leading to a foreign body reaction
This can lead to abscess formation, or tracks to teh skin in a ‘pilonidal sinus’ with foul discharge
Most common in obese males, particularly from Asia/Middle East
What is the treatment of a pilonidal sinus?
Excision of the sinus tract and primary closure, with pre-op antibiotics
Hygiene and hair removal advice should be given
What are the treatments for perianal warts?
Podophyllin paint, cryotherapy or surgical excision
Those secondary to syphiis can be treated with penicillin
How are perianal infections examined?
Diagnosis = usually straightforward, however deep sepsis higher up the anal canal may require EAU or imagine
Any discharging area near the anus should be assumed to communicate with the anorectic until proven otherwise
Operative exploration is often the first diagnostic test, although MRI can be used
What is a ‘fistula in ano’
A track that communicates between the skin and the anal canal / rectum c.f. a sinus which is a track, leading from source of the infection to the surface
Usually the result of an abscess discharging to form a fistula.
Symptoms are thus of an anorectal abscess, followed by recurrent episodes of infection
Describe the aetiology of a fistula in ano
TB Chron's Diverticular disease Rectal carcinoma Immunocompromised individuals e.g. HIV
What investigations can be done for a fistula in ano?
Examination of the tract is extremely painful and thus should only be done under anaesthetic
MRI
Endoanal USS
What is Goodsall’s rule?
Relates the external opening of an anal fistula (compared to the transverse anal line) to its international opening
Posterior fistulas will have a curved track with their opening in the posterior midline
Anterior fistulas will have a direct opening into the anal cavity
Exception: anterior fistulas that lie more than 3cm from the anus, which may drain like posterior fistulas with a. curved track to the posterior midline
What is the management of fistula in ano?
Superficial and Low level fistulae are laid open to heal by secondary intention (fistulotomy)
High fistulae (involve the continence muscles of the anus) Amy be injected with fibrin glue or a fistula plug
If these methods fail, a seton suture gradually tightened over time can be used to maintain continence (ensures the sphincter is fixed by scar tissue before the tract is divided by tightening the suture
Recurrent fistulae associated with Chron’s may respond to metronidazole
What is an anal fissure
Tear in the sensitive anal canal distal to the dentate line, producing pain on deecation
What are the symptoms of an anal fissure?
Pain, worse on defecation, lasting for hours afterwards
Associated constipation
Pruritus ani
Bleeding on defecation
What will you see on examination of an anal fissure?
Midline longitudinal tear in the rectal mucosa (90% posterior, 10% anterior due to parturition
‘Sentinel pile or mucosal tag at the external aspect
PR may not be possible due to pain and sphincter spasm
proctoscopy and sigmoidoscopy should be performed under anaesthesia to exclude other anorectal diseases. Enlarged nodes in the groin suggest a complicating factor
What is the cause of anal fissure?
Hard faeces, with 10% of anterior tears due to parturition
Thought to occur at the midline more as the blood supply to this area is worse, and thus, healing is difficult
Rarer causes: infections (syphilis/herpes), trauma, Chron’s, anal cancer and psoriasis
What is the management of anal fissure?
May heal spontaneously, with local anaesthetic ointments and lubricant laxative
High fibre diet, plenty of fluids and bulk forming laxative
If chronic: GTN cream used to relax anal sphincter and allow torn epithelium to heal (can give headaches)
Bo-TOx injection has the same effect and can last up to 8 weeks, but there is a small incidence of incontinence afterwards
Intractable fissures or recurrent cases may require a sphincterotomy (submucosal division of the external sphincter under GA)
