General - large bowel disease

Question 1

Appendicitis

Answer 1

Inflammation of the appendix
Most commonly affects those in their second/third decade

Question 2

Appendicitis pathophysiology

Answer 2

Typically caused by direct luminal obstruction, usually secondary to a faecolith, lymphoid hyperplasia, impacted stool or rarely a tumour
When obstructed, commensal bacteria in the appendix can multiply -> acute inflammation
Reduced venous drainage and localised inflammation can result in increased pressure within the appendix, in turn can result in ischaemia
Left untreated -> ischaemia within the appendiceal wall can result in necrosis -> perforation

Question 3

Appendicitis risk factors

Answer 3

Family history
Ethnicity – more common in Caucasians
Environmental – summer

Question 4

Appendicitis clinical features

Answer 4

Pain – initially peri-umbilical, classically dull and poorly localised, but later migrates to the right iliac fossa, where it is well-localised and sharp
Vomiting, anorexia, nausea, diarrhoea or constipation
Examination – rebound tenderness and percussion pain over McBurney’s point, guarding, severe cases
- Rovsing’s sign: RIF fossa pin on palpation of the LIF
- Psoas sign: RIF pain with extension of the right hip (appendix in a retrocaecal position)

Question 5

Appendicitis investigations

Answer 5

Urinalysis, pregnancy test
Routine bloods – FBC, CRP, serum B-hCG if ectopic pregnancy has not been excluded
Imaging – ultrasound is first line if the differential includes gynaecological pathology, CT is able to delineate multiple differentials including GI and urological causes

Question 6

Appendicitis management

Answer 6

Definitive treatment – laparoscopic appendicectomy
Appendix should routinely be sent to histopathology to look for malignancy

Question 7

Appendicitis complications

Answer 7

Perforation – if left untreated can perforate and cause peritoneal contamination
Surgical site infection
Appendix mass
Pelvis abscess – fever with a palpable RIF mass, confirmed on CT scan, management is usually with abx and percutaneous drainage of abscess

Question 8

Colorectal cancer aetiology

Answer 8

Originate from the epithelial cells, most commonly an adenocarcinoma
Develop via a progression of normal mucosa to colonic adenoma to invasive adenocarcinoma (adenoma carcinoma sequence)
Certain genetic mutations:
- Adenomatous polyposis coli (eg. FAP)
- Hereditary nonpolyposis colorectal cancer

Question 9

Colorectal cancer risk factors

Answer 9

Increasing age
Male gender
Family history
Inflammatory bowel disease
Low fibre diet
High processed meat intake, smoking, excess alcohol

Question 10

Colorectal cancer clinical features

Answer 10

Change in bowel habit, rectal bleeding, weight loss, abdominal pain and symptoms of anaemia
Right-sided colon cancers – abdominal pain, iron-deficiency anaemia, palpable in RIF, often present late
Left-sided colon cancers – rectal bleeding, change in bowel habit, tenesmus, palpable mass in LIF/PR exam

Question 11

Colorectal cancer screening

Answer 11

Every 2 years to men and women aged 60-75 years
FIT test is used – utilises antibodies against human haemoglobin to detect blood in faeces
Positive samples – offered an appointment with a specialist nurse and further investigations via colonoscopy

Question 12

Colorectal cancer investigations

Answer 12

Routine bloods – FBC, LFTs, clotting, CEA can be used to monitor disease progression
Imaging – gold standard for diagnosis is via colonoscopy with biopsy
Once diagnosis is made:
- CT chest/abdomen/pelvis to look for distal metastases and local invasion
- MRI rectum (for rectal cancers only)
- Endo-anal ultrasound (for early rectal cancers, T1/T2 only)
Biopsy samples will be assessed using TNM staging, histological subtyping, grading and assessment of lymphatic, perineural and venous invasion

Question 13

Colorectal cancer surgical management

Answer 13

Mainstay of curative management
1) Right hemicolectomy/extended right hemicolectomy – surgical approach for caecal tumours/ascending colon tumours
2) Left hemicolectomy – surgical approach for descending colon tumours
3) Sigmoidcolectomy – sigmoid colon tumours
4) Anterior resection – high rectal tumours
5) Abdominoperineal resection – low rectal tumours
6) Hartmann’s procedure – used in emergency bowel surgery (eg. obstruction/perforation), involves a completed resection of the recto-sigmoid colon

Question 14

Colorectal cancer chemotherapy

Answer 14

Indicated typically in patients with advanced disease
FOLFOX – folinic acid, fluorouracil & oxaliplatin
Newer biologic agents or immunotherapies

Question 15

Colorectal radiotherapy

Answer 15

Can be used in rectal cancer, most often as neo-adjuvant treatment and can be given alongside chemotherapy
Particular use in patients with rectal cancers which look on MRI to have a ‘threatened’ circumferential resection = pre-operative long-course chemo-radiotherapy to shrink the tumour

Question 16

Crohn’s disease pathophysiology

Answer 16

Any part of the GI tract, commonly targets the distal ileum/proximal colon
Characterised by transmural inflammation in the affected region of bowel, producing deep ulcers and fissures (‘cobblestone’ appearance), skip lesions
Non-caseating granulomatous inflammation
Fistulae commonly form

Question 17

UC vs Crohn’s disease

Answer 17

Site involvement – large bowel in UC, entire GI tract in CD
Inflammation – mucosal only in UC, transmural inflammation in CD
Microscopic changes – crypt abcess formation, reduced goblet cells, non-granulomatous in UC, non-caseating granulomatous in CD
Macroscopic changes – continuous inflammation, pseudo polyps and ulcers may form in UC, skip lesions, fissures, deep ulcers, fistula formation in CD

Question 18

Crohn’s disease risk factors

Answer 18

Strong family history
Smoking

Question 19

Crohn’s disease clinical features

Answer 19

Episodic abdominal pain and diarrhoea – colicky pain and diarrhoea may contain blood/mucus
Systemic symptoms – malaise, anorexia and low-grade fever, malabsorption & malnourishment
Oral aphthous ulcers
Perianal disease

Question 20

Crohn’s disease extraintestinal manifestations

Answer 20

MSK – enteropathic arthritis, nail clubbing or with metabolic bone disease
Skin – erythema nodosum, pyoderma gangrenosum
Eyes – episcleritis, anterior uveitis or iritis
Hepatobiliary – PSC, cholangiocarcinoma, gallstones
Renal – renal stones

Question 21

Crohn’s disease investigations

Answer 21

Routine bloods
Faecal calprotectin, stool sample
Colonoscopy is gold standard investigation with biopsies taken to confirm the diagnosis
Imaging – CT scan abdomen pelvis in severe Crohn’s disease, MRI, EUA with proctosigmoidoscopy may be considered to examine and treat perianal fistulae present

Question 22

Crohn’s disease management

Answer 22

Should be referred to a gastroenterologist
Inducing remission – fluid resus, nutritional support, prophylactic heparin, corticosteroid therapy as first line, immunosuppressive agents/biological agents can be trialled as rescue therapy if then needed
Maintaining remission – azathioprine, smoking cessation, colonoscopic surveillance is offered to people who have had the disease > 10 years with > 1 segment of bowel affected
Surgical management – failed medical management or severe complications

Question 23

Crohn’s disease complications

Answer 23

GI – fistula, stricture formation, recurrent perianal fistulae, GI malignancy
Extraintestinal – malabsorption, osteoporosis, increased risk of gallstones, increased risk of renal stones

Question 24

Diverticular disease

Answer 24

Diverticulum = outpouching of the bowel wall
Diverticulosis – presence of diverticula
Diverticular disease – symptoms arising from the diverticula
Diverticulitis – inflammation of the diverticula
Diverticular bleed – where the diverticulum erodes into a vessel & causes a large volume painless bleed

Question 25

Diverticular disease pathophysiology

Answer 25

Aging bowel becomes weakened over time, movement of stool within the lumen will cause an increase in luminal pressure Results in an outpouching of the mucosa through the weaker areas of the bowel wall Bacteria can overgrow within the outpouchings, leading to inflammation -> can sometimes perforate

Question 26

Diverticular disease risk factors

Answer 26

Age Low dietary fibre intake Obesity Smoking Family history NSAID use

Question 27

Diverticular disease clinical features

Answer 27

Diverticulosis – asymptomatic and found incidentally during routine colonoscopy or CT imaging Diverticular disease – intermittent lower abdominal pain, typically colicky in nature & may be relieved by defecation (other symptoms – altered bowel habit, associated nausea and flatulence) Acute diverticulitis – acute abdominal pain, typically sharp in nature & normally localised in the LIF pain, worsened by movement Examination – localised tenderness, alongside features of systemic upset

Question 28

Diverticular abscess

Answer 28

Diverticular abscess occurs as a sequelae in complicated diverticulitis Around <5cm can generally be managed conservatively with IV abx, if any bigger, then radiological drainage is first-line treatment Complicated multi-loculated abscesses will need surgical intervention (laparoscopic washout/Hartmann’s procedure)

Question 29

Diverticular disease investigations

Answer 29

Lab tests – initial routine blood tests, group and save, VBG, urine dipstick Imaging – CT abdomen-pelvis is investigation of choice (thickening of colonic wall, pericolonic fat stranding, abscesses, localised air bubbles, free air) Flexible sigmoidoscopy is a good initial approach (suspected uncomplicated diverticular disease)

Question 30

Diverticular disease management

Answer 30

Uncomplicated diverticular disease – can be managed as an outpatient with simple analgesia and encouraging oral fluid intake Patients with diverticular bleeds – can often be managed conservatively as most cases will be self-limiting Those that fail to respond to conservative management may warrant embolization/surgical resection

Question 31

Acute diverticulitis management

Answer 31

Most can be managed conservatively – abx, IV fluids and analgesia Symptoms typically improve within 2-3 after the initiation of treatment for uncomplicated cases Clinical deterioration should prompt repeat imaging to check for disease progression/complication

Question 32

Diverticular disease surgical management

Answer 32

Required in those with perforation with faecal peritonitis or overwhelming sepsis Usually involves a Hartmann’s procedure (sigmoid colectomy with formation of an end colostomy) An anastomosis with reversal of colostomy may be possible may be possible at a later date

Question 33

Diverticular disease complications

Answer 33

Diverticular stricture – following repeated episodes of acute inflammation, can result in large bowel obstruction, sigmoid colectomy is required Fistula formation – nearly always require surgical intervention - Colovesical fistula – gas bubbles in the urine (pneumoturia) - Colovaginal fistula – copious vaginal discharge or recurrent vaginal infections

Question 34

Pseudo-obstruction

Answer 34

Disorder characterised by dilatation of the colon due to an adynamic bowel in the absence of mechanical obstruction Most commonly affects the caecum and ascending colon

Question 35

Pseudo-obstruction pathophysiology

Answer 35

Thought to be due to an interruption of the autonomic nervous supply to the colon resulting in the absence of smooth muscle action in the bowel wall Variety of causes: - Electrolyte imbalance or endocrine disorders - Medication - Recent surgery, severe illness or trauma - Neurological disease

Question 36

Pseudo-obstruction clinical features

Answer 36

Abdominal pain Abdominal distension Constipation Vomiting Examination – abdomen will be distended and tympanic

Question 37

Pseudo-obstruction investigations

Answer 37

Initial blood tests should be performed to assess for biochemical/endocrine Plain abdominal films (AXR) – show bowel distension Should undergo CT abdomen-pelvis scan with IV contrast – will show dilatation of the colon

Question 38

Pseudo-obstruction management

Answer 38

Most cases can be managed conservatively – patients should be made nil-by-mouth and started on IV fluids If patient is vomiting an NGT should be inserted to aid decompression Endoscopic decompression will be mainstay of treatment if not resolved in 24-48 hours -> insertion of a flatus tube & allows region to decompress, IV neostigmine may also be trialled if suitable Surgical management – non-responding cases may require segmental resection +/- anastomosis

Question 39

UC pathophysiology

Answer 39

Characterised by diffuse continual mucosal inflammation of the large bowel beginning in the rectum and spreading proximally Backwash ileitis = distal ileum cab become affected in the ileocaecal valve is not competent Histological changes – non-granulomatous inflammation of the mucosa and submucosa, crypt abscesses and goblet cell hypoplasia

Question 40

UC clinical features

Answer 40

Bloody diarrhoea PR bleeding, mucus discharge, increased frequency and urgency of defecation and tenesmus Systemic symptoms – malaise, anorexia and low-grade pyrexia Clinical examination – generally unremarkable

Question 41

UC extra-intestinal manifestations

Answer 41

MSK – enteropathic arthritis, nail clubbing Skin – erythema nodosum (tender red/purple subcutaneous nodules, typically on the shins) Eyes – episcleritis, anterior uveitis or iritis Hepatobiliary – primary sclerosing cholangitis (chronic inflammation & fibrosis of the bile ducts)

Question 42

UC investigations

Answer 42

Routine bloods Faecal calprotectin and stool sample Imaging – definitive diagnosis is via colonoscopy with biopsy (continuous inflammation with possible ulcers & pseudopolyps visible) Acute exacerbations – AXR or CT imaging - AXR features: mural thickening and thumbprinting; in chronic cases of UC a lead-pipe colon

Question 43

UC management (inducing remission)

Answer 43

Aggressive fluid resus, nutritional support and prophylactic heparin Medical management – IV corticosteroid agents, immunosuppressive agents, biological agents

Question 44

UC management (maintaining remission)

Answer 44

Remission of the disease can be maintained using immunomodulators, typically 5-ASAs eg. mesalazine/sulfasalazine or azathioprine Colonoscopic surveillance is offered to people who have had the disease for >10 years with >1 segment of bowel affected Referred to IBD-nurse specialists and patient-support groups

Question 45

UC management (surgical management)

Answer 45

Indications: disease refractory to medical management, toxic megacolon or bowel perforation Elective causes – total proctocolectomy is curative (patient will require an end ileostomy) Many patients for disease control will initially undergo a subtotal colectomy with ileo-rectal anastomosis or panproctocolectomy with ileo-pouch anal anastomosis

Question 46

UC complications

Answer 46

Toxic megacolon – present with severe abdominal pain, abdominal distension, pyrexia and systemic toxicity Colorectal carcinoma Osteoporosis Pouchitis

Question 47

Volvulus

Answer 47

Twisting of a loop of intestine around its mesenteric attachment, resulting in a closed loop bowel obstruction Affected bowel can become ischaemic due to compromised blood supply Most volvuli occur at the sigmoid colon and are a common cause of large bowel obstruction

Question 48

Volvulus risk factors

Answer 48

Increasing age Neuropsychiatric disorders Resident in a nursing home Chronic constipation/laxative use Male gender Previous abdominal operations

Question 49

Volvulus clinical features

Answer 49

Clinical features of bowel obstruction Colicky pain, abdominal distension and absolute constipation occur earlier Rapidity of the onset (over a few hours) and degree of abdominal distension Examination – abdomen is often very tympanic to percussion

Question 50

Volvulus investigations

Answer 50

Routine bloods CT scan abdomen-pelvis with contrast – much more sensitive and specific for bowel obstruction & also identifies the site and cause AXR – coffee-bean sign arising from the LIF, if the ileocaecal valve is incompetent – also show signs of small bowel dilatation

Question 51

Volvulus conservative management

Answer 51

Most patients are treated conservatively initially with decompression by sigmoidoscope and insertion of a flatus tube Flatus tube is often left is situ for up to 24 hours after initial decompression to allow the continued passage of contents

Question 52

Volvulus surgical management

Answer 52

Indications for surgery: colonic ischaemia/perforation, repeated failed attempts at decompression, necrotic bowel noted at endoscopy - Usually a Hartmann’s procedure Patients with recurrent volvulus – may choose to have an elective procedure to prevent further recurrence

Question 53

Volvulus complications

Answer 53

Bowel ischaemia and perforation Risk of recurrence Complications from stoma Mortality from surgery