Diverticula disease and colonic and anal disorders Flashcards
Define diverticular disease and diverticulitis
A diverticulitum refers to an out-pouching of the mucosa through the muscular wall with the peritoneum still intact. Diverticulitis refers to the inflammation of these diverticula.
Clinical features of diverticular disease and diverticulitis
Diverticular disease
- Most patients are asymptomatic
- Altered bowel habit
Diverticulitis
- Left iliac fossa pain and pyrexia
- Abrupt intermittent PR bleeding may occasionally occur
Investigations for diverticulitis
- Bloods - ↑WCC, ↑CRP
- Contrast enhanced CT - best modality to look for abscess formation or active inflammation
- Flexible sigmoidoscopy - may be necessary to exclude a more sinister cause
Management of asymptomatic divertcular disease
- Encourage a high fibre diet
- Relieve constipation with laxatives
Management of mild diverticulitis
- Encourage oral hydration and bowel rest
- 7-day course of oral co-amoxiclav and metronidazole
Management of severe diverticulitis
- Patients should be admitted and made NBM from admission
- IV fluids, analgesia and supportive therapy should be offered
- Commence IV antibiotics promptly (based on local guidance)
- Consider surgery if indicated
Management of complications of diverticulitis
- Perforation - urgent surgical resection
- Major haemorrhage - radiologically guided embolisation
- Abscess - IV antibiotics and US/CT guided drainage
- Strictures - surgical resection or stent insertion
What are polyps?
Polyps are abnormal growths that protrude from a membranous surface. They may occur anywhere in the body that has a mucus membrane, from the nasal cavity or uterine cavity to the colon.
Definition of adenomas
How can adenomas be subdivided?
Adenomas are composed of benign, dysplasia tissue and arise from columnar epithelium or glandular tissue. They can be subdivided based on their glandular morphology, into tubular, tubulovillous or villous subtypes.
Features of adenomas which are associated with a higher risk of malignant transformation
- Size >1.5cm
- Multiple polyps >5
- Sessile and villous nature
NICE recommends regular colonoscopic surveillance after the initial polypectomy.
What should be the frequency of follow up?
- Annually: ≥5 polyps or ≥3 with at least one >1cm
- Every 3 years: >3 polyps or at least one >1cm
- Every 5 years: 1-2 polyps, all of which <1cm
Familial adenomatous polyposis
Inheritance?
Genetics?
- Inheritance: autosomal dominant
- Genetics: APC gene on chromosome 5
Clinical features of familial adenomatous polyposis
Presents with hundreds to thousands of adenomas, which develop predominantly in the colon and rectum. They can also arise in the small bowel and stomach.
Management of familial adenomatous polyposis
- 90% of patients with FAP will eventually develop cancer if untreated
- Early prophylactic colectomy and lifelong follow-up is the best treatment option to prevent cancer development
- First-degree relatives should be offered genetic testing
Define colorectal cancer
Colorectal cancer refers to a carcinoma that arises from the mucosa of the colon or rectum. About two-thirds of CRCs occur in the colon and the remaining third in the rectum. The majority are adenocarcinomas (95%), typically developing from a polyp.
Epidemiology of colorectal cancer
- Third most common cancer worldwide
- Slight male preponderance, especially rectal cancer
- Usually presents in the sixth decade
- Lower incidence in Africa and Asia
Risk factors for colorectal cancer
- Family history of CRC or inherited polyposis syndromes
- Diet consisting of ↑red meat and saturated fat,
Clinical features of colorectal cancer
Presentation is dependent on the site of the lesion:
- Right sided lesion
- Occult bleeding, anaemia
- Constipation
- Late obstruction
- Colicky abdominal pain and weight loss
- Left sided lesion
- Fresh PR bleeding
- Loose stools
- Early obstruction
Occasoinally, patients may present as an emergency with acute bowel obstruction.
Investigations for patients with possible colorectal cancer
- Colonoscopy
- First line in patients without significant comorbidities
- Enables direct visualisation and biopsies to be obtained
- Staging imaging
- Contrast enhanced CT chest/abdominal/pelvis to evaluate tumour size, extent and spread
- PET scans may be used to detect distal metastasis
- Further imaging
- Pelvic MRI for better assessment of rectal disease
- MRI liver may be indicated to identify liver mets
Colorectal cancer staging
Management of localised rectal or colonic disease
- Neoadjuvant radiotherapy may be offered to reduce recurrence
- Offer laparoscopic surgical resection
- Offer adjuvant chemotherapy (capecitabine) to patients with high risk stage 2 disease and above
Management of metastatic colorectal cancer
- Consider surgical resection if both primary and metastatic tumours are resectable
- Offer chemotherapy in combination with biologics (eg bevacizumab) in patients with unresectable disease
- Managment of extra-hepatic and hepatic metastasis
- Paliative care
Treatment of lung metastasis in colorectal cancer
Radiofrequency ablation (RFA) of lung metastasis
Management of bone metastasis in colorectal cancer
Denosumab is recommended for prevention of pathological fractures secondary to bony metastasis
Management of hepatic metastasis
- Consider surgical resection or radiofrequency ablation
- Otherwise offer chemotherapy in combination with cetuximab
Definition of haemorrhoids
Haemorrhoidal cushions are vascular mucosal cushions that line the anal canal and function to help with the control of stool passage. These cushions may become dilated, enlarged and may eventually protrude through the anus.
Aetiology of haemorrhoids
- Usually caused by straining secondary to constiption
- Can also be caused by increased intra-abdominal pressure (eg pregnancy, abdominal mass)
Haemorrhoids classification
- First degree - no prolapse
- Second degree - prolapse on straining but reduces spontaneouly
- Third degree - prolapse but manually reducible
- Fourth degree - permanently prolapsed
Clinical features of haemorrhoids
- Patients frequently present with fresh PR bleeding
- They may occasionally have severe perinatal pain associated with thrombosis as a result of stranulated haemorrhoids
Management of haemorrhoids
Management mainly involves pain relief and the treatment of constipation (increased dietary fibre and stool softeners may be useful)
Definition of anal fissure and cause
An anal fissure is a break in the musosal squamous epithelium of the lower anal canal.
It is usually caused by excessive straining and trauma secondary to the passage of hard stools.
Clinical features of anal fissure
- Patients tend to present with very severe anal pain and fresh PR bleeding
- PR examination is almost impossible due to the pain
Definition of an abscess
An abscess is the infection of soft tissue resulting in the accumulation of pus within its walled off cavity.
Anorectal abscess clinical features
- Patients present with extreme pain, often unable even to sit
- Anal/perianal discharge and occasionally systemic upset (pyrexia)
- Spontaneous rupture of these abscesses may predispose to fistulae formation
Management of anorectal abscess
Management often requires surgical drainage and healing with secondary intention. Antibiotics may have a role to play in very early disease.
