Lower GI Bleeding

Question 1

Causes

Answer 1

diverticulosis, ischaemic or infective colitis, haemorrhoids, malignancy, angiodysplasia, inflammatory bowel disease, or radiation procititis.

Question 2

Diverticulosis

Answer 2

Diverticulosis is the most common cause of lower gastrointestinal bleeding. Diverticula are outpouchings of the bowel wall that are composed only of mucosa, most commonly in the descending and sigmoid colon.

Their incidence increases with age. Diverticular disease bleeds are classically painless, whilst diverticulitis is classically painful.

Question 3

Haemmorhoids

Answer 3

Haemorrhoids are pathologically engorged vascular cushions in the anal canal that can present as a mass, with pruritus, or fresh red rectal bleeding.

The blood is classically on the surface of the stool or toilet pan, rather than mixed in with it. Large haemorrhoids can also thrombose which can be extremely painful.

Question 4

Malignancy

Answer 4

With any case of PR bleeding, especially in the elderly population, malignancy should be suspected, as this may be a colorectal cancer.

Question 5

Clinical Assessment

Answer 5

Nature of bleeding, including duration, frequency, colour of the bleeding, relation to stool and defecation
Associated symptoms, including pain (especially association with defaecation), haematemesis, PR mucus, or previous episodes
Family history of bowel cancer or inflammatory bowel disease

A PR examination is essential for every patient presenting with haemotochezia, allowing assessment for any rectal masses or anal fissures

Question 6

Investigations

Answer 6

All patients presenting with rectal bleeding should have routine bloods* (FBC, U&Es, LFT, coagulation studies) and a Group and Save requested (as a minimum).

The presence of an elevated serum urea to creatinine ratio (>30:1) suggests an upper GI source of bleeding being more likely. Stool cultures are also useful to exclude infective causes.

Question 7

haemodynamically stable pt investigations

Answer 7

flexible sigmoidoscopy for further assessment, importantly to exclude left-colonic pathology (especially malignancy) and can often be performed as an outpatient. If flexible sigmoidoscopy proves inconclusive, patients may undergo a full colonoscopy

Question 8

haemodynamically unstable

Answer 8

upper GI endoscopy must also be considered in such patients and can be performed immediately before colonoscopy, alongside ongoing resuscitation.

Question 9

Why is CT angiography used?

Answer 9

CT angiography (or radionuclide labelled red-cell scintigraphy) can be used in patients with colonoscopy was non-diagnostic, endoscopic haemostasis unsuccessful, or with ongoing bleeding and haemdynamic instability. Not only can this aid in the identification of culprit bleeding vessels but also permits for potential therapeutic intervention if possible, via arterial embolisation.

Question 10

Management

Answer 10

Any acute large rectal bleed warrants careful resuscitation, with a standard A to E approach, gaining 2 large bore cannulae, IV fluid, and blood products crossmatches (as required).

Question 11

Treatment

Answer 11

endoscopic haemostasis methods include injection (typically diluted adrenaline), contact and non-contact thermal devices
mechanical therapies (endoscopic clips and band ligation)

angiography, arterial embolisation if the vessel is identifiable and sufficient diameter

Question 12

Surgical Intervention

Answer 12

Surgical intervention may be required in patients with ongoing lower GI bleeding with instability (or requiring continued transfusion), where endoscopic and radiographic treatment has failed.