This document discusses lower gastrointestinal bleeding, its causes, and management. The most common causes of lower GI bleeding are diverticulosis (5-42% of cases), ischemia (6-18% of cases), and anorectal issues like hemorrhoids or anal fissures (6-16% of cases). While diverticular disease is very common, bleeding from it is rare. However, it is still the most common cause of lower GI bleeding due to its high prevalence. Other potential causes discussed include angiodysplasia, inflammatory bowel conditions, radiation colitis, infections, and colon cancer. Colon cancer is one of the most common cancers and its prevalence increases with age, obesity, red meat consumption, and can

1. Lower GI Bleeding
Hakan Şentürk

2. Bleeding arising distal to Treitz
• Hemotochezia
• Much less life-threatining in comparison to upper GI bleeding
• Eighty-five percent stops spontaneously
• Mortality rate 2-4 %
• Ten to fifteen percent of the cases with hemotochezia, the bleeding
source is proximal to Treitz.

3. ETIOLOGY
●Anatomic (diverticulosis)
●Vascular (angiodysplasia, ischemic, radiation-induced)
●Inflammatory (inflammatory bowel disease, infectious)
●Neoplastic

4. Lower GI bleeding: Etiology
●Diverticulosis – 5 to 42 percent
●Ischemia – 6 to 18 percent
●Anorectal (hemorrhoids, anal fissures, rectal ulcers) – 6 to 16 percent
●Neoplasia (polyps and cancers) – 3 to 11 percent
●Angiodysplasia – 0 to 3 percent
●Postpolypectomy – 0 to 13 percent
●Inflammatory bowel disease – 2 to 4 percent
●Radiation colitis – 1 to 3 percent
●Other colitis (infectious, antibiotic associated, ischemic, colitis of unclear etiology)
– 3 to 29 percent
●Small bowel/upper GI bleed – 3 to 13 percent
●Other causes – 1 to 9 percent
●Unknown cause – 6 to 23 percent

5. DIVERTICULAR DISEASE
• Diverticulum is a sac-like protrusion of the intestinal wall.
• While the prevalence of diverticular disase is 20 % before the age of
40, it reaches 60 % by the age of 60
• However, bleeding is rare in diverticular disease, its very high
prevalence makes it the number one etiology in lower GI bleeding
• Bleeding is the result of erosion of the feeding vessel.
• Risk factors for diverticular bleeding include aspirin and nonsteroidal
anti-inflammatory drug (NSAID) use, advanced age, obesity, physical
inactivity, hypertension, ischemic heart disease, chronic renal
insufficiency, and hyperlipidemia.
• Divertiular bleeding mostly happens without diverticulitis.

8. ANGIODYSPLASIA
• Angiodysplasia refers to dilated, tortuous submucosal vessels. The
walls of these blood vessels are composed of endothelial cells that
lack smooth muscle.
• Bleeding from angiodysplasia is a rare event
• It is of venous origin and hence less brisk in contradistinction to
diverticular bleeding.
• It is contolled by endoscopic means.

10. COLITIS
• Infectious Colitis
• Ischemic Colitis
• Inflammatory Bowel Disease

12. COLON CANCER
• The most common GI cancer and one of the most frequent in all
cancers.
• Its prevalence reach to 3 % in general population.
• It is more common in obese people and meat-eaters.
• It is frequently metastatic in diagnosis
• It may, partly, be prevented by screening colonoscopy.