Common Causes of Lower GI Bleeding

Question 1

3 locations for GI bleeding

Answer 1

UGI: esophagus, stomach, duodenum
Small bowel bleeding
Lower GI: colon or rectum

Question 2

Hematochezia

Answer 2

Passage of red blood or maroon coloured stools

Question 3

Left vs right colon bleeding

Answer 3

Left: typically bright red in colour
Right: dark or maroon coloured (mixed with stool). Can also present as melena

Question 4

Is the colour of the stool diagnostic?

Answer 4

No, since melena can be from right colon or small bowel, and hematochezia from massive UGIB

Question 5

Causes of LGI bleeding

Answer 5

C-HAND
Colitis: infectious, inflammatory, ischemic
Hemorrhoids
Angiodysplasia
Neoplastic
Diverticulosis

Question 6

Dentate line

Answer 6

Separates the rectum from anus

Below you have innervation, above you do not

Question 7

Pain in hemorrhoids vs fissues

Answer 7

Hemorrhoids: usually painless (unless below dentate line)
Fissures: painful

Question 8

3 ways to diagnose hemorrhoids

Answer 8

History
DRE
Endoscopy

Question 9

3 ways to manage hemorrhoids/fissues

Answer 9

Lifestyle: high fiber, lots of fluid, dont strain
Medications: hydrocortisone based ointments/suppositories, fissures can be treated with topical Nitro or Diltiazem ointments (vasodilators of the anal canal)
Surgical: banding, hemorrhoidectomy, botox in sphincter for fissures

Question 10

Diverticulosis

Answer 10

Sac like protrusions of the colon wall
Common in older age
Associated with Western diet
Most in the sigmoid colon (high pressure)
Clinical presentation: large volume bleeding, painless, most stop spontaneously

Question 11

Clinical presentation of diverticulitis

Answer 11

Pain
Fevers
High WBC
Not typically bleeding

Question 12

4 investigations/management of diverticulosis

Answer 12

Resuscitation: ABCs
Colonoscopy: limited utility as its hard to find which one is bleeding
Angiography: start with CT, therapy applied directly
Surgery: segmental resection, only for persistent bleeding and instability despite resuscitation

Question 13

3 different types of colitis

Answer 13

Inflammatory
Ischemic
Infectious

Question 14

Ischemic colitis

Answer 14

Reduction of blood flow from the mesenteric vasculature
Colorectal circulation has protective collateral, but limited in areas like the rectosigmoid junction and splenic flexure
Caused by non-occlusive colonic ischemia, embolic occlusion, or mesenteric vein thrombosis

Question 15

2 main places to get ischemic colitis

Answer 15

Rectosigmoid junction

Splenic flexure

Question 16

Clinical manifestations of ischemic colitis

Answer 16

Acute abdominal pain followed by diarrhea and mild rectal bleeding
Patients are often elderly with other CV risk factors
If colonic infarction develops, can lead to sepsis, peritonitis, and gangrene

Question 17

3 ways to diagnose ischemic colitis

Answer 17

Lab: anemia, high serum lactate, high WBC
CT scan
Colonoscopy

Question 18

Treatment for ischemic colitis

Answer 18

Supportive
Antibiotics in patients with severe ischemia and peritonitis (get general surg involved)
Blood thinners only for mesenteric venous thrombosis
Treat underlying CV factors

Question 19

Clinical manifestations of infectious colitis

Answer 19

Acute onset diarrhea, nausea, vomiting, fevers

Question 20

Antibiotic for severe bloody diarrhea (high fever, more than 2 days) from infectious colitis

Answer 20

Ciprofloxacin 500 mg BID for 3-5 days

If EHEC suspected (blood diarrhea, pain, no fever, exposure) then don’t use antibiotics due to risk of HUS

Question 21

Angiodysplasia

Answer 21

Dilated, tortuous submucosal vessels
Associated with end stage renal disease, aortic stenosis, and age
Most commonly in the cecum and right colon
Typically a slow, occult bleed (Fe deficiency)
Treat with argon plasma

Question 22

Clinical presentation of colon cancer

Answer 22

Bright red blood from left sided lesions, and maroon stools/melena from right sided
Most commonly will see occult iron deficiency
Often have altered bowel habits
Can cause bowel obstruction and also metastasis
Treatment is really surgery

Question 23

10 high risk features of a lower GI bleed

Answer 23

Hemodynamic instability
Significant comorbid illness
Advanced age
Bleeding in a hospitalized patient
Known diverticulosis
Blood thinners
Persistent bleeding
Elevated urea
Profound anemia
Altered mental status

Question 24

Labs to order for GI bleed

Answer 24

CBC
Electrolytes
Creatinine
BUN (Blood urea nitrogen)
INR (time it takes to clot)
Liver enzymes
In a large UGI bleed will have an elevated BUN to creatinine ratio (> 20:1)

Question 25

CT angiography

Answer 25

Contrast enhanced CT scan
Widely available, fast, non invasive
Highly sensitive
Cons: contrast, radiation, no therapeutic capability

Question 26

Angiography

Answer 26

Performed by interventional radiology
After CT angiography
Transcatheter embolization can stop bleeding from a distal vessel
No need for bowel prep

Question 27

What is the Hb count to transfuse blood?

Answer 27

Under 80