diseases of colon

Question 1

colon sphincters

Answer 1

ileocecal valve, internal and external anal sphincters

Question 2

Does colon have villi

Answer 2

no

Question 3

Functions of colon

Answer 3

absorption of water and ions (ascending), bacterial fermentation of nonabsorbed nutrients (transverse and descending), storage and elimination (descending and rectum)

Question 4

irritable bowel disease symptoms

Answer 4

Suggestive symptoms (e.g., diarrhea, crampy abd pain, bleeding) lasting > 2 weeks , Negative work-up for other causes of colitis (infection, ischemia, medications), Extraintestinal symptoms

Question 5

How is irritable bowel disease diagnosed

Answer 5

Direct visualization and biopsy

Question 6

signs/symptoms of ulcerative colitis

Answer 6

Diarrhea, Weight loss, Fatigue, Lower abd pain, Hematochezia , Mucus in stool, Tenesmus

Question 7

signs/symptoms of Crohns

Answer 7

Diarrhea, Weight loss, Fatigue, Mid or lower abd pain, Nausea/vomiting, Fistula symptoms

Question 8

For Crohns and ulcerative colitis List: bowel region, fistulae/abscess, strictures and distribution

Answer 8

Crohns: entire GI tract, fistulae and abscesses common, strictures common, skip lesions. UC: Colon, NO fistulaes or abscesses, no strictures, diffuse

Question 9

For Crohns and ulcerative colitis List: location of inflammation, location and type of ulcers, presence of fibrosis, presence of granulomas

Answer 9

Crohns: transmural inflammation, deep linear ulcers, lots of fibrosis, 20% get granulomas. UC: mucosal +/- smooth muscle inflammation, superficial confluent ulcers, mild to no fibrosis, no granulomas

Question 10

For Crohns and ulcerative colitis List whether it has each of the following: obstruction, malabsorption, malignant potential, recurrence after colectomy, toxic megacolon

Answer 10

Crohns: obstruction YES, malabsorption YES, malignant potential with colonic involvement, recurrence after colectomy common, toxic megacolon NO. UC: obstruction NO, malabsorption NO, malignant potential YES, recurrence after colectomy NO, toxic megacolon YES

Question 11

Extraintestinal manifestations of ulcerative colitis

Answer 11

eye: scleritis, episcleritis. Skin: Pyoderma gangrenosum (ulcers on lower extremities), erythema nodosum (nodules with erythrodermous patch). Liver: Primary sclerosing cholangitis (PSC- fibrosis of hepatic bile ducts). Joints: Sacroiliitis, Ankylosing spondylitis

Question 12

How is IBD (crohns and UC) treated

Answer 12

Corticosteroids during flares, 5-aminosalicylates, immunomodulators, TNF-alpha antagonists, surgery (colectomy, partial small bowel resection or stricturoplasty)

Question 13

Colon cancer and UC

Answer 13

risk increases with disease duration

Question 14

What is microscopic colitis

Answer 14

Chronic secretory diarrhea that is watery and non-bloody (4-10 stools per day, minimal nocturnal or fasting symptoms). Mainly occurs in females age 50-80, autoimmune but trigger is unknown.

Question 15

Microscopic colitis diagnosis

Answer 15

Colonoscopy usually normal. Biopsy shows Lymphocytic infiltration of mucosa and SM (LC) and Thickened collagenous band (CC)

Question 16

Types of microscopic colitis

Answer 16

Based on histology: lymphocytic (chronic inflammation) or collagenous (thickened subepithelial collagen band with lymphocytic surface injury)

Question 17

microscopic colitis treatment

Answer 17

antidiarrheals (loperamide, diphenoxylate), bismuth, topical steroids

Question 18

Ischemic colitis triggers

Answer 18

vasospasm, dehydration, hypotension, cardiopulmonary insult (MI, PE)

Question 19

ischemic colitis locations

Answer 19

watershed vascular areas: splenic flexure, rectosigmoid

Question 20

Ischemic colitis presentation

Answer 20

• Abrupt-onset, crampy, lower abdominal pain. Urgent need to defecate. Mild diarrhea and/or hematochezia.
• Abrupt-onset, crampy, lower abdominal pain. Urgent need to defecate. Mild diarrhea and/or hematochezia.

Question 21

ischemic colitis endoscopic findings

Answer 21

edema, ulceration +/- bleeding confined to vascular region

Question 22

ischemic colitis recovery time

Answer 22

1-2 weeks

Question 23

Ischemic colitis diagnosis:

Answer 23

Colonoscopy or flexible sigmoidoscopy with biopsy are gold standard. A KUB x ray may show thumbprinting of colon mucosa, but not sensitive. Also, contrast CT may show colon wall thickening, pericolonic inflammation or decreased perfusion

Question 24

Less common causes of ischemic colitis

Answer 24

vasculitis (lupus), substance abuse, meds (estrogen), protein C/ S deficiency, Factor V leiden deficiency, marathon running

Question 25

ischemic colitis treatment

Answer 25

support, antibiotics, volume support

Question 26

Symptoms of infectious colitis

Answer 26

•Inflammatory diarrhea +/- hematochezia. Short duration, recent travel/sick contacts, Abx use,

Question 27

Risk factors for diverticulosis

Answer 27

western countires (low fiber diets, increased intracolonic pressure), >50% are in elderly

Question 28

Symptoms and cause of diverticular hemorrhage

Answer 28

usually in right colon, vasa recta withing dome of diverticulum. Causes painless Painless hematochezia, often heavy, typically stops w/in 2-3 days. Does NOT occur with diverticulitis

Question 29

What is acute diverticulitis

Answer 29

Fecolith obstructs diverticulum causing distension from bacterial gas and neutrophils, microperforation, abscess, macroperforation with peritonitis.

Question 30

Acute diverticulitis symptoms

Answer 30

LLQ pain, nausea, fever

Question 31

Diverticulitis management

Answer 31

Diagnose with CT or MRI. Treat with oral/ IV antibiotics, abscess drainage and/or surgery. Strictures may require dilation or resection

Question 32

Etiologies of lower GI bleeding

Answer 32

diverticulosis, arteriovenous malformations, colitis, neoplasm, radiation colitis, post-polypectomy or biopsy, internal hemorrhoids, rectal ulcer, anal fissure,

Question 33

Causes of colonic obstruction

Answer 33

adenocarcinoma of colon or rectum (90%), volvulus, benign strictures from acute divertiulitis.

Question 34

Obstructive colon cancer prodrome

Answer 34

change in stool frequency or caliber

Question 35

Volvulus

Answer 35

typically involves the cecum or sigmoid colon, where a colonic loop twists around on its mesentery, resulting in strangulation and luminal obstruction

Question 36

colonic obstruction presentation

Answer 36

diffuse or upper abdominal discomfort, distension, and nausea/vomiting. The emesis may be feculent. Absence of stool passage (obstipation)

Question 37

How is colonic obstruction treated

Answer 37

surgical resection or metal stent