Colon & Rectum Flashcards
Define:
Diverticulosis
Diverticular disease
Diverticulitis
Diverticulosis = diverticula are present
Diverticular disease = diverticula are present and symptomatic
Diverticulitis = inflammation of a diverticulum
What is diverticulosis and what causes it?
Mucosal herniation through muscle coat
Found in the sigmoid colon
Low fibre intake is thought to lead to high intraluminal pressures which force the mucosa to herniate through the muscle layers of the gut at weak points
Most commonly an incidental finding
What are the typical clinical features of diverticular disease?
LIF pain/tenderness
Sepsis
Altered bowel habit
What are some common complications of diverticular disease?
Pericolic abscess Perforation Haemorrhage Fistula Stricture
Treatment of uncomplicated diverticulitis
IV fluids
Bowel rest
IV antibiotics
Treatment of complicated diverticulitis
Hartmann’s procedure - resection of the rectosigmoid colon with closure of the rectal stump and formation of an end colostomy
Percutaneous drainage
Laparoscopc lavage and drainage
Acute & Chronic colitis
Causes?
Symptoms?
Dianosis?
Infective colitis; UC; Crohn’s; ischaemic
Diarrhoea + blood; abdo cramps; dehydration; sepsis; weight loss; anaemia
Diagnosis - plain AXR; sigmoidoscopy with biopsy; stool cultures barium enema
Ischaemic colitis Who does it tend to occur in? Most common artery? Presentation? Gold standard test? Treatment
Elderly, arteriopaths
Inferior mesenteric artery - ranges from mild ischaemia to gangrenous colitis
Lower left sided abdo pain +/- bloody diarrhoea
Colonoscopy with biopsy
Barium enema shows characteristic “thumb print” of submucosal swelling
Fluid and IV antibiotics; embolisation
Sigmoid volvulus What is this? Who does it occur in? What is seen on AXR? Treatment?
The bowel twists on its mesentery, which can produce severe, rapid, strangulated obstruction
Occurs in elderly, constipated, co-morbid patient
“Inverted u” loop of bowel that can look like a coffee bean
Treatment is flatus tube, sigmoid colectomy is also sometimes required
What is peristalsis in the colon initiated by?
Peristalsis is induced by the release of serotonin (5-HT) from neuroendocrine cells in response to luminal distension.
Serotonon activated 5-HT4, which in turn results in the activation of sensory neurones
What are the three types of constipation?
Briefly describe each.
- Normal transit through the colon - there is normal rate and stool frequency, but patients believe they are constipated
- Defecatory - a paradoxical contraction rather than the normal relaxation of the puborectalis and external anal sphincter during straining may prevent defecation
- Slow transit constipation - occurs predominantly in young women who have infrequent bowel movements
Megacolon
What is it?
What causes it?
What disease should be ruled out in young patients with this?
A number of congenital and acquired conditions in which the colon is dilated.
In many cases, it is secondary to chronic constipation and in some parts of the world Chagas’ disease (caused by a blood sucking bug) is a common cause.
Hirschsprung’s disease - a disease which presents in the early years of life, where an aganglonic segment of the rectum (megarectum) gives rise to constipation and subacute obstruction
What is the management of faecal incontinence?
Initial management is bowel habit regulation
Loperamide is the most potent antidiarrhoeal agent which also increases internal sphincter tone
What site is most commonly affected in ischaemic colitis?
Splenic flexure
Colonic polyp
What is this?
Benign or malignant?
An abnormal growth of tissue projecting from the colonic mucosa
They can be benign or malignant - need histology to tell them apart
