Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI / Hepatology > 29 - Diseases of the Colon and Rectum > Flashcards

29 - Diseases of the Colon and Rectum Flashcards

1
Q

Colon & Rectum - Development

A 
First trimester of gestation
Distal midgut (Cecum to splenic flexure) & hindgut (splenic flexure to rectum)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Colon & rectum - Size

A

1m long

2L capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Colon & Rectum - Regions

A 
Cecum
Ascending Colon
Transverse Colon
Descending Colon
Sigmoid Colon
Rectum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Colon - 5 layers

A 
Mucosa
Submucosa
Circular muscle
Longitudinal muscle
Serosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Colon - Haustra

A

Tonic contractions of rings of circular muscle (plicae semilunares coli)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Colon - Circular muscle layer control

A

Thin layer of cells, interstitial cells of Cajal on submucosal surface of smooth muscle layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Colon & Rectum - Histo

A

Mucosa:
Columnar cells
Goblet cells
Enteroendocrine cells (mainly located in the crypts)

No Villi

Epithelial cells proliferate in lower parts of crypts, migrate toward surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Blood supply: Cecum, Ascending Colon, Transverse Colon

A

SMA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Blood Supply: Transverse Colon, Descending Colon, Sigmoid Colon, Rectum

A

IMA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Venous drainage

A

Analogous to arterial supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Colon - Neuronal supply

A

Intrinsic and extrinsic neurons

Extrinsic - Autonomic

Parasympathetic innervation supplied by vagal fibers (midgut derivatives) or the nerves of the pelvic plexus from sacral spinal cord (hindgut derivatives)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Colon & Rectum purpose

A

Maintain fluid & electrolyte balance
Salvage products of intra-colonic fermentation
Store waste materials
Recover 1.5L fluid per day (mostly in proximal colon)
1 - 2 bowel movements/day
Can absorb sodium against high electrochemical gradient!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Colon & Rectum - Pharmacology

A

Most drugs already absorbed by that point

EXCEPT Sulfasalazine (used to treat UC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Sulfasalazine

A

Composed of sulfapyridine (sulfonamide antibacterial) linked by a diazo bond with 5-Aminosalicylic acid (5-ASA, or mesalamine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

5-ASA

A

The active therapeutic moiety of sulfasalazine.

The sulfapyridine just prevents 5-ASA from being absorbed earlier. The diazo bond is broken by bacterial action.

5-ASA decreases inflammation in the colon.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Microbiome

A

10^10 organisms/mL

Represent a pool of metabolic enzymes

Anaerobes, can thrive in low-oxygen tension

Modify oxygen tension, pH, mucopolysaccharide composition & hydration capacity of stool solids.

Normal flora protects against pathogenic bacterial proliferation. Homeostasis between types of bacteria.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Colon & Rectum - Vascular Diseases

A

Ischemic colitis
Diverticular bleeding
Hemorrhoidal bleeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Colon & Rectum - Neoplastic Diseases

A

Colon polyps

Colorectal cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Colon & Rectum - Infectious Diseases

A

Appendecitis
Bacerial/Viral Colitis
Clostridium Difficile
Diverticulitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Colon & Rectum - Mechanical Diseases

A

Volvulus

Large bowel obstruction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Colon & Rectum - Immunologic Diseases

A

IBD
Collageneous/Microscopic Colitis
Ileus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Colon & Rectum - Motility Diseases

A

Ileus

IBD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Ischemic Colitis - Presentation

A

Crampy, mild LLQ abdominal pain

Urge to defecate

Pass bright red (or maroon) blood mixed with stool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Ischemic Colitis - Morphologic Changes

A

Vary with duration & severity of injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Ischemic Colitis - Watershed Areas

A

Splenic Flexure
Rectosigmoid

Due to limited collateral flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Ischemic Colitis - Mildest injuries

A

Reversible

Mucosal & submucosal hemorrhage & edema

with or without partial necrosis of the mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Ischemic Colitis - Unresorbed Hemorrhage

A

Overlying mucosa sloughs off, forming an ulcer.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Ischemic Colitis - Prolonged Severe Ischemia

A

Muscularis propria is damaged, replaced with fibrous tissue.

Stricture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Ischemic Colitis - Most Severe

A

Trans-mural infarction
Gangrene
Perforation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Diverticulae

A

Herniations of colonic mucosa through defects in the muscularis layer, resulting in formation of pseudodiverticulae (wall is only made of mucosa and serosa)

Common. Found in 50% of individuals over age 60 on western diet, and 2/3 of patients over 80

Cause unknown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Hypothesis of diverticulae origins

A 
Low fiber western diet
Lower stool volume
Smaller stools
More colon segmentation
High pressures in colonic lumen
Mucosa forced through wall of colon where nutrient vessels enter.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Diverticulosis

A

Only 5% of these patients bleed significantly

Still, however, one of the most common causes of Lower GI Bleed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Diverticulae most common in

A

Left colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Diverticular bleeding most common in

A

Right colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Diverticular bleed - Pathway

A

Diverticulum expands
Small arterioles running adjacent bleed briskly.

Painless!!

Most episodes stop spontaneously.

50% recur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Diverticular bleeding

A

Sudden
Painless
May be severe

May present with hypovolemia before blood appears in the rectum (a large amount of blood can be stored in the colon)

Nutrient arteriole ruptures at the base of the diverticulum (maybe due to a fecalith impaction?)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Small amounts of blood in stool, or intermittent rectal bleeding

A

Probably not diverticular bleed.

More likely hemorrhoids, proctitis, polyps or carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Iron deficiency anemia

A

NEVER explained by diverticular bleeding.

Typically a long-standing microcytic anemia, where patients are unaware that they’re losing blood.

Diverticular bleeds are FAR too overt and large volume for that.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

NSAIDs or Aspirin

A

Increase likelihood of diverticular bleeds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Diverticular Bleeding - Treatment

A 
Resuscitate patient (IV fluids, packed RBC)
Assess blood loss
Administer ADH
Selectively embolize the bleed
Surgery may be necessary
Often the bleeding stops spontaneously
We may also have to clip the diverticulum.

After the bleeding stops, we must do a colonoscopy to check.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Differentiate Diverticular Bleed from Upper GI Bleed

A

BUN Elevated in an Upper GI Bleed because the body resorbs the blood.

Sometimes also a lavage via NG tube would also reveal an upper GI bleed too.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Tagged Radionuclide Red Blood Cell Scan

A

Localize where the bleeding is coming from.

Send patient to interventional radiology where they can administer ADH, then selectively embolize by angiography.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Hemorrhoidal Bleeding

A

Occur in >50% of individuals in USA

Most common cause of Lower GI Bleed in adults

Present with scant hematochezia usually.

Occasionally bleed massively

Path unknown

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Hemorrhoidal Bleeding - Conservative Treatment

A

Topical anti-inflammatory agents

Increased dietary fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Hemorrhoidal Bleeding - More extreme measures

A 
Rubber band ligation
Injection sclerotherapy
Cryosurgery
Electrocoagulation
Laser ablation
Photocoagulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Lower GI Bleed - Differential

A 
Diverticular
Hemorrhoidal
Arteriovascular Malformations
Stercoral Ulcers
Neoplasms
Mechanical Injury (post-polypectomy bleeding)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Arteriovascular Malformation - Colon

A

Typically leads to iron deficient anemia.

If patient is on Warfarin, it can lead to massive bleed, but this is less common.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Stercoral Ulcers

A

Pressure necrosis
Patients constantly impacted
Stool pressing against the wall causes the wall to necrose.

Mentally-impaired patient not receiving enough attention to their bowel movements.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Colon Cancer

A

Can bleed, but typically presents with an iron deficiency anemia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Colon Neoplasia

A 
Colorectal adenoma
Colorectal adenocarcinoma
Colorectal hyperplastic polyp
Colorectal sessile polyp
Carcinoids of the colon and rectum
Leiomyomas of the colon and rectum
Gastrointestinal stromal cell tumors of the rectum and colon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

FAP

A

Familial Adenomatous Polyposis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Appendicitis - Lifetime risk in western populations

A

7%

Slightly higher male predominance in 2nd and 3rd decades of life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Appendix

A

Previously thought to be vestigial
Now thought to have a role in intestinal immunity

Has many lymphoid follicles
# of follicles peaks between ages 10 - 30.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Appendicitis - Causes

A

70% due to obstruction of the appendiceal lumen:

Fecaliths
Tumors
Parasites
Lymphoid hyperplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Obstruction of the appendiceal lumen is followed by

A 
Mucus secretion
Bacterial overgrowth
Increasing intra-luminal pressure and wall tension
Vascular congestion
Gangrene and perforation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Appendicitis - Atypical presentation

A

Appendix lies in atypical positions (Retrocecal, retroileal)

Increased risk of perforation (due to delayed diagnosis)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Most common microbes for appendicitis

A

E. Coli is most common gram-negative
B. Fragilis is most common anaerobe, second only to E. Coli overall

Most infections are polymicrobial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Appendicitis - Diagnosis

A 
H&P are major
Abdominal pain is primary symptom.
Classically peri-umbilical, but may be epigastric or suprapubig
After 1 - 12 hours, pain migrates to RLQ (McBurney's Point), becomes more intense
Anorexia
Nausea
Rovsing's Sign
Fever
Elevated WBC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Appendicitis - When should you question your diagnosis?

A

If vomiting precedes abdominal pain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

McBurney’s Point

A

2/3 of the distance from umbilicus to ASIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Rovsing’s Sign

A

Palpation of LLQ produces pain in RLQ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Appendicitis - Imaging

A

Abdominal CT = Gold Standard
Dilated appendix
Edema
Mesenteric stranding around the appendix in the RLQ

63
Q

Appendicitis - Treatment

A

Appendectomy for nearly all patients.

Give prophylactic antibiotics to prevent infection.

Patient presents late in course after perforation, we give a course of antibiotics and see what happens

64
Q

Appendectomy - Most common complication

A

Infection.

This is why we give single dose broad spectrum antibiotics as prophylaxis. Without these, the wound infection rate is 9 - 30% in early appendicitis. Late appendicitis, this approaches 80%.

With ppx, infection risk is

65
Q

Appendectomy - Perforation

A

Rates of 20 - 30% over the last 70 years
Precedes surgical evaluation in most cases
Increases risk of second laparotomy by more than 250%

66
Q

Diverticulitis - Average Age

A

44 years

67
Q

Appendicitis - Average Age

A

Much Younger

68
Q

Diverticulitis - Duration

A

3.3 days

69
Q

Appendicitis - Duration

A

24 hours

70
Q

Diverticulitis - Location

A

RLQ of abdomen

71
Q

Appendicitis - Location

A

Epigastrium initially, then RLQ

72
Q

Diverticulitis - Nausea

A

20%

73
Q

Appendicitis - Nausea

A

80%

74
Q

Infectious causes of colitis - Bacterial

A 
Campylobacter
C. Difficile
E. Coli
Salmonella enteritidis
Shigella
Yersinia
Aeromonas
75
Q

Infectious causes of colitis - Viral

A

Adenovirus
Norwalk virus
Rotavirus
Others

76
Q

Infectious causes of colitis - Parasitic/Protozoal

A

Entamoeba histolytica
Giardia lambia
Cryptosporidium
Cyclospora

77
Q

Food Poisoning - Microbes

A 
B. Cereus
C. Perfringens
Salmonella
Staphylococcus
Vibrio
Shigella
Campylobacter
E. Coli
Yersinia Enterocolitica
Listeria Monocytogenes
78
Q

Clostridium Difficile

A

Most common cause of nosocomial infectious diarrhea

Present in 3 - 5% of healthy, asymptomatic adults.

79
Q

Clostridium Difficile - Range of Clinical Presentation

A

Varies.

Mild self-limited illness
Diarrhea
Resolves soon after withdrawal of offending antibiotic

OR

Severe pseudomembranous colitis
Fever
Profuse watery, non-bloody diarrhea
Toxicity
Toxic megacolon
Significant mortality

Small bowel rarely affected
Diarrhea often associated with fever, crampy abdominal pain, leukocytosis

80
Q

C. Diff - More serious complications

A

Toxic megacolon

Colonic perforation

81
Q

Toxic Megacolon

A

The colon shuts down
Adynamic ileus
Severe risk of gangrene and perforation.

82
Q

C. Diff - Endoscopy

A

Pseudomembranes!!

Looks almost like oral thrush

83
Q

C. Diff - Risk factors - Antibiotics

A

Within 4 - 8 weeks of presentation:

Clindamycin
Ampicillin
Amoxicillin
Cephalosporins
Fluoroquinolones (eg Levofloxacin or Ciprofloxacin)
84
Q

C. Diff - Risk factors - Non antibiotics

A 
Hospitalization
Recent surgery
Uremia
Crohn's Disease
Severe concurrent infection
Recent cancer chemotherapy
85
Q

C. Diff - Diagnostic

A

Gold standard - Tissue Culture Assay

Rarely have to do that, though. Frequently just send a stool sample for latex particle agglutination immunoassays(Sensitivity 87%, Specificity 99%)

Endoscopic/Histologic pseudomembranes are pathognomonic

86
Q

C. Diff - Treatment

A

Offending antibiotic should be discontinued if possible

Oral antibiotic therapy prescribed for 14 days

If patient can’t handle oral medication, give metronidazole 500mg IV q 8 hours

Do NOT give IV vancomycin. It will not work. PO will, though.

87
Q

C. Diff - Surgery

A

In the cases of:

Refractory colitis
Toxic megacolon
Perforation

88
Q

C. Diff - Metronidazole

A

500 mg po TID
OR
250 mg po QID

Response rate: 98%
Relapse rate: 7%

89
Q

C. Diff - Vancomycin

A

125 mg po QID

Response rate: 96%
Relapse rate: 18 %

90
Q

C. Diff - Bacitracin

A

25,000 U QID

Response rate: 83%
Relapse rate: 34%

91
Q

C. Diff - Cholestyramine

A

4 gm po TID

Response rate: 68%
Relapse rate: Unknown

Binds to the toxin of C. Diff and helps patient expel that toxin.

92
Q

C. Diff - Relapses

A

10 - 20% of cases

Usually due to incomplete eradication of initial infection

Spores can live for 2 weeks after completion of antibiotic course

93
Q

C. Diff - Relapse treatment

A

Metronidazole 500 mg po TID

PLUS

Rifampin 300 mg po BID

OR

Vancomycin 125 mg po QID and TAPER steadily (over 6 weeks) down to one tablet every 2nd or 3rd day.

94
Q

Diverticulitis

A

Infected diverticulum

Most frequently occurs in sigmoid colon

10 - 25% of patients with previously-recognized diverticulosis

Risk increases over time. 10% after 5 years with diverticulosis, 35% after 20 years with diverticulosis

60% of patients with a first episode will have mild illness, can be treated as outpatients with abx

95
Q

Diverticulitis - Antibiotic regimen

A

Should cover:

Enterobacteriacea
Bacteroides
Pseudomonas (less frequent)
Enterococci (less frequent)

96
Q

Diverticulitis - Path

A

Inspissated fecal matter in a diverticulum may form a fecalith

Causes impaction within diverticulum
Local mucosal inflammation
Ensuing necrosis
Microperforation of macroperforation

97
Q

Diverticulitis - Microperforation

A

Initially contained by pericolonic tissues (mesentery, fat, adjacent organs)

See peritoneal air, but you don’t see contrast spilling out. Air has perforated through the diverticulum, but then it healed.

This results in an inflammatory mass or phlegmon

Can be treated with antibiotics, bowel rest, supportive care.

98
Q

Diverticulitis - Repeated Microperforation

A

May lead to fibrosis of colonic wall, then stricture

99
Q

Diverticulitis - Macroperforation

A

Result of free perforation with generalized peritonitis

Needs surgery

100
Q

Diverticulitis - Peri-diverticular abscess

A

May result in a fistula

101
Q

Diverticulitis - Imaging

A

Abdominal CT

Fat stranding and/or a mass in the LLQ

102
Q

Diverticulitis - Clinical Picture

A

LLQ pain in 93 - 100% of patients
Change in bowel habits
Fever (86% of patients)
Leukocytosis (in up to 90% of patients)

If fistula to bladder formed:
Frequency, urgerncy, pneumaturia, fecaluria

LLQ abdominal tenderness
Mass may be palpable
Involuntary guarding & rebound tenderness (if peritonitis)

103
Q

Diverticulitis - Diagnostic Studies

A

Abdominal/Pelvic CT with IV contrast

Colonoscopy or Sigmoidoscopy not done in acute setting (fear of worsening perf)

104
Q

Diverticulitis - Treatment (Mild Disease)

A

Liquid or low residue diet
Oral antibiotics 7 - 10 days:
Metronidazole + either Levofloxacin, TMP-Sulfa, Ciprofloxacin or Amoxicillin-Clavulanate

105
Q

Diverticulitis - After resolution of acute attack

A

Colonoscopy 4 - 6 weeks to rule out colitis, polyps, cancer

106
Q

Diverticulitis - Surgery

A

Not indicated after first episode, since only 20 - 30% recur.

Should be considered 4 - 6 weeks after THIRD episode inflammation has resolved

107
Q

Diverticulitis - Recurrence

A

Usually take place within 5 years of the initial episode

108
Q

Diverticulitis - Indications for hospitalization

A

Severe pain
Inability to tolerate oral diet
Failure of symptoms to resolve with outpatient therapy
Clinical toxicity (High fever, worsening leukocytosis)

109
Q

Vovlulus

A

Twisting of colon around the mesentery

180 degrees minimum for significant obstruction to occur

If intraluminal pressure exceeds capillary perfusion pressure, vascular compromise may occur. Leads to ulcer, necrosis, grangrene and perforation.

If obstruction persists, strangulation is initiated by venous thrombosis, followed by arterial occlusion and infarction.

110
Q

Volvulus - Locations

A

Stomach
Cecum
Sigmoid

111
Q

Volvulus - Predisposing Factors

A

Congenital or Acquired:

Long, redundant (from long-standing constipation), mobile sigmoid colon
Elongated, freely movable sigmoid mesentery
Narrow mesenteric attachment frequently scarring at the base (from repeated twisting)

112
Q

Sigmoid Volvulus

A

Axial torsion of sigmoid volvulus usually occurs in counterclockwise direction around mesenteric base.

Attacks can be subacute or acute fulminating.

60% of patients with sigmoid volvulus report prior attacks that spontaneously resolved

113
Q

Sigmoid Volvulus - Barium Enema

A

Bird’s beak in the sigmoid. No more contrast beyond that point very dilated loop of bowel.

114
Q

Sigmoid Volvulus - Epi

A

Highest prevalence - Underdeveloped countries with high-residue diet with vegetable fiber.

Accounts for 3 - 10% of colonic obstructions in the western world

M:F
3:1 (men have longer sigmoids, women have wider pelvises)

115
Q

Most common cause of Lower Bowel Obstruction in pregnancy

A

Sigmoid Volvulus

116
Q

Chronic constipation leads to

A

Lengthening of the sigmoid

117
Q

Sigmoid volvulus - Physical findings

A

Markedly distended abdomen
Tympanic
No (or low) bowel sounds

118
Q

Sigmoid volvulus - Diagnosis

A

Plain films are diagnostic in 2/3 or cases

Contrast studies:
Bird’s beak
Ace of spades

119
Q

Sigmoid volvulus - Therapeutic Goals

A

Relief of acute torsion

Prevention of recurrence

120
Q

Sigmoid volvulus - Treatment

A

85 - 90% of subjects can be decompressed by sigmoidoscopy (if mucosa is not ischemic or necrotic)

121
Q

Sigmoid volvulus - Recurrence

A

High recurrence rate

Mortality higher after recurrence than it was after initial episode.

122
Q

Sigmoid volvulus - Surgery

A

Best to do it electively after 2nd or 3rd occurrence. Typically a complete sigmoid resection is indicated.

If patient presents emergently and is peritoneal, surgery may be indicated earlier.

123
Q

Large Bowel Obstruction

A

Result of any mechanical obstruction in the large intestine not permitting the passage of stool or gas.

Can be secondary to tumor, stricture, extrinsic compression

124
Q

Large Bowel Obstruction - Presentation

A

Obstipation
Abdominal Distention
Abdominal Pain

Can be toxic on presentation, depending on degree of ischemia caused

125
Q

Large Bowel Obstruction - Perforation

A

Occurs if underlying mechanical obstruction is not treated.

126
Q

Large Bowel Obstruction - Treatment

A

Surgery

Enteral stents

127
Q

Large Bowel Obstruction - Imaging (Tumor)

A

Barium enema:
Apple core lesion in the colon
Very dilated upstream colon

128
Q

Crohn’s Disease

A

Full thickness inflammation of bowel wall.

Results in:
Strictures
Fistulas
Abscesses

Relapsing remitting course treated by topical anti-inflammatory agents & immunomodulators

129
Q

Ulcerative Colitis

A

Superficial colitis of bowel beginning in rectum and extending proximally contiguously for varying lengths
(Proctitis vs. Pancolitis)

Clinically, patients present most often with bloody diarrhea, weight loss

Total colectomy - Curative

130
Q

Collagenous / Lymphocytic Colitis

A

Microscopic Colitis

Typically elderly patients on long-standing NSAIDS

Syndrome:
Watery diarrhea
No specific endoscopic or radiographic abnormalities of the bowel

May be the same disease with a part of the spectrum containing collagen, but may be separate. We don’t know.

Relapsing remitting course over years

131
Q

Collagenous Colitis

A

Watery Diarrhea
Sub-epithelial collagen band in colonic mucosa
Chronic inflammatory infiltrate in lamina propria

132
Q

Lymphocytic colitis

A

Watery diarrhea
No collagen band in the colonic sub-epithelium
Intraepithelial lymphocytes present

133
Q

Lamina propria of normal colonic mucosa

A

Scattered lymphocytes, monocytes, eosinophils

If there is subepithelial collagen, it is very narrow (3 microns or less in diameter)

134
Q

Collagenous Colitis - Histo

A

Thickened subepithelial collagen layer (20 -60 microns)

Collagen band not a marker for disease severity, no correlation between thickness and age/duration of disease

135
Q

Collagenous / Lymphocytic Colitis - Appears like

A

Celiac Sprue. If they don’t get better on a gluten free diet, they may have collagenous/lymphocytic colitis.

136
Q

Collagenous / Lymphocytic Colitis - Endoscopy

A

NORMAL

137
Q

Collagenous / Lymphocytic Colitis - Symptoms

A 
Secretory diarrhea, so persists even when fasting
Watery stools
8 stools/day average
Cramping pain
Nausea
Weight loss
Fecal urgency
Fecal incontinence
138
Q

Collagenous Colitis - Epi

A

50 - 70 year olds
M:F
20:1

139
Q

Lymphocytic Colitis - Epi

A

51 years old
M:F
1:1

140
Q

Collagenous/Lymphocytic Colitis - Physical Exam

A

Unremarkable or mild abdominal tenderness

141
Q

Collagenous Colitis - Associated with

A 
Rheumatoid Arthritis
Seronegative Polyarthritis
Thyroid disease
Diabetes Mellitus
CREST Syndrome
142
Q

Lymphocytic Colitis - Associated with

A

Rheumatoid Arthritis
Sicca Syndrome
Uveitis
Diabetes Mellitus

143
Q

Collagenous / Lymphocytic Colitis - Diagnosis

A

Characteristic histopathologic changes in colonic mucosal biopsies from patient with chronic watery diarrhea

Blood/stool studies are USELESS!!!!

144
Q

Collagenous / Lymphocytic colitis - Treatment

A

Remove NSAID use
Bismuth subsalicylate tablets induce remission

Mild/Intermittent - Antidiarrheal drugs:
Diphenoxylate with Atropine, loperamide, psyllium or methylcellulose

Troublesome/Persistent - Anti-inflammatory agents such as sulfasalazine and mesalamine

Unresponsive to anti-inflammatories - Corticosteroids

Last resort - Surgery

145
Q

Adynamic Ileus or Pseudo-Obstruction

A

Failure of effective peristalsis without mechanical obstruction

146
Q

Adynamic Ileus or Pseudo-Obstruction - Causes

A

Metabolic abnormalities (uremia, electrolyte abnormalities)
Drugs (Narcotics, opiates, anti-cholinergics)
Local or systemic infections (C. Diff)
Non-infectious Inflammatory Processes (Pancreatitis)
Neurogenic causes (spinal cord injury)
Post-operative Ileus (Ogilvie Syndrome)

147
Q

Adynamic Ileus or Pseudo-Obstruction - Presentation

A

Abdominal Pain
Lack of bowel sounds
or
High pitched bowel sounds

148
Q

Distinguish Ileus from Obstruction

A

Barium Enema
Obstruction - Contrast doesn’t make it all the way across the colon.
Ileus - Air fluid levels

149
Q

Ileus - Management

A

Supportive care through fluid & electrolyte management
Remove precipitating agent
Decompress EARLY

150
Q

Ileus - If patient doesn’t get better with only supportive care

A

Try neostygmine

Get a surgical consult, in case emergency surgery is needed (rare).

151
Q

Irritable Bowel Syndrome

A

22% of the US population
28% of GI visits

Chronic disorder (unknown origin). Maybe visceral hypersensitivity?

Alterations in bowel habits and exacerbations/remissions of abdominal pain and discomfort

Diagnosis of exclusion

152
Q

Irritable Bowel Syndrome - Presentation

A

Abdominal pain/discomfort
Relieved with defecation
Associated with a change in frequency of bowel movements and/or altered stool form
Passage of mucus or bloating/distention

153
Q

Irritable Bowel Syndrome - Types

A

Diarrhea predominant
Constipation predominant
Mixed

154
Q

Irritable Bowel Syndrome - Treatment

A 
Bulking agents
Anti-diarrheal agents
Smooth muscle relaxants
Pro-kinetic agents
Antidepressants
Anxiolytics
Psychologic and behavioral treatments.

GI / Hepatology (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions