Colonic Disease Flashcards
1
Q
What are the segments of the large intestine?
A
Cecum, colon, and rectum
2
Q
What is a cecum?
A
A blind diverticulum of the colon that is more functional in herbivores and is the site of bacterial fermentation
3
Q
What are the components of the colon?
A
Ascending, transverse, and descending
4
Q
How much of the GI length is comprised by the colon?
A
20-25% total length
5
Q
What are the layers of the large intestine?
A
Mucosa- submcosa- muscularis- serosa
6
Q
T/F: The large intestinal mucosa possesses villi but no goblet cells.
A
False
Mucosal layer of the LI does not have villi but has many mucus secreting cells
7
Q
What are crypts of Leiberkuhn?
A
- Tubular crypts that extend through the entire thickness of hte mucosa
- High mitotic index
- Absorbtion of vitamins and minerals
8
Q
How long is the cell turnover rate in the large intestine compared to the small intestine?
A
4-7 days
Slower than the SI
9
Q
What are the functions of the large intestine?
A
- Conversion of digested materials into feces
- Expulsion of fecal matter
- Mucous and bicarbonate secretion
- Absorption of LOTS of water and sodium chloride
10
Q
What is the function of the mucus and bicarbonate secretion function of the large intestine?
A
- Protection of mucosa/epithelium
- Lubricates and binds fecal component
- Neutralizes acidic content of feces
11
Q
What are clinical signs of colonic disease?
A
Diarrhea OR constipation Blood in or on the stool Mucus on stool Tenesmus Dyschezia Urgency
No weight loss or vomiting usually unless severe disease (more common in cats)
12
Q
What are some potential physical exam findings in a patient with colonic disease?
A
Typically normal
Anal or peri-anal irritation
Weight loss in advanced disease
Dehydration or fever
Constipation
Must assess for hind end neurologic disease
13
Q
What may you find on a rectal palpation in an animal with colonic disease?
A
- Compression or obstrutive lesions
- Hernias
- Able to assess nature of stool
14
Q
What are some general disease processes found in the colon?
A
- Inflammatory
- Neoplasia
- Obstructive
- Motility disorders
- Metabolic or endocrine disorders (secondary)
- Infectious diseases
15
Q
What can you find on CBC that can help you characterize colonic disease?
A
- Non-regenerative anemia: chronic systemic disease
- Regenerative anemia: blood loss
- Leukocytosis: Inflammation, infection, neoplasia
- Eosinophilia: Addison’s disease, parasites, mast cell tumors, hypereosinophilic syndromes
16
Q
What serum chemistry findings can help you characterize colonic disease?
A
- Hypoproteinemia: disease extends to small intestine
- Hyperglobulinemia: FIP, infectious, neoplasia
- Hypercalcemia: neoplasia, fungal
- Hypoglycemia: septic abdomen, paraneoplastic, Addison’s
- Hyponatremia: Addison’s, pseudo-addisons (whipworms), effusions
17
Q
What are radiographs useful for when assessing colonic disease?
A
Obstructions, constipation, megacolon, masses, lymphadenopathy
Negative contrast colonogram for intraluminal masses
18
Q
What is the importance of assessing the sublumbar LN in colonic patients?
A
Enlarged sublumbar LN can compress the rectum leading to obstruction and constipation in an otherwise healthy gut
19
Q
What can be assessed on ultrasound of the large intestine?
A
- Ileocolic junction, cecum, and colon up to the pelvis
- Thin walled struction that are typically gas or feces distended
- Masses, thickening of the wall, evidence of perforation, effusion
- Regional LN enlargement
20
Q
When would MRI or CT be approriate?
A
Evaluation of intrapelvic structures- distal colon, rectum, and anal canal
21
Q
When is a colonoscopy useful?
A
- Non-GI disease is ruled out
- Evidence of gross disease is present on imaging and need a biopsy
- No abnormal findings on imaging and CS support LI disease
22
Q
What is the prep required for a colonoscopy?
A
- 24-36 hour fast
- Enemas before and under GA
- Oral polyethylene glycol (osmotic laxative) or other laxatives
23
Q
What does a normal colon look like?
A
Pink, smooth, glistening with frequent peristalsis
24
Q
What parasites can you find in the colon?
A
Trichuris vulpis Heterobilharzia americana Tritrichomonas foetus Giardia Histoplasmosis Pythium
25
What is Trichuris vulpis and what does it do?
Whipworm in dogs that causes acute to chronic large bowel diarrhea
- Fecal oral transmission of eggs
- Live in cecum and colon
CS: may be asymptomatic, hematochezia, mucoid diarrhea, tenesmus
26
How do you diagnose and treat T. vulpis?
Non-specific clin path findings: can see hyperkalemia and hyponatremia (pseudo-addisons disease)
Fecal floatation, ELISA, colonoscopy
Treatment: 3 months of fenbendazole
27
What is heterbilharzia?
- Trematode found in the gulf coat states that causes chronic large intestinal diarrhea
- Reservoirs in mice, rabbits, racoons, and nutria
28
What are the clinical signs and clin path findings of heterobilharzia?
CS: vomiting, large bowel diarrhea, weight loss, inappetence
Clin path: hypoalbuminemia, hyperflobulinemia, increased liver enzymes, hypercalcemia
29
How do you diagnose and treat heterobilharzia and what is the progosis?
Dx: fecal sediment, PCR, ELISA, biopsy
Tx: Fenbendazole with praziquantel
Prognosis: fair to good in acute disease, guarded in chronic disease with liver cirrhosis
30
What is entamoeba histolytica?
- Uncommon disease of dogs and cats caused by an ameoba
- Lives in cecum and colon primarily but can go to other organs
- Zoonotic; fecal-oral
31
What are the clinical signs of entamoeba?
- Diarrhea
- Hematochezia
- Tenesmus
- Systemic illness if disseminated (weight loss and inappetence most common)
32
How do you diagnose and treat entamoeba?
Dx: Trophozoites in cysts in feces, colonic wall scrape (best method), colonoscopy biopsy
Tx: Metronidazole and furazolidone
33
What is tritrichomonas foetus and what does it cause?
Protozoa of young cats
Causes waxing and waning LI diarrhea that is typically self limiting but can be serious in immune compromised animals
34
How do you diagnose and treat tritrichomonas?
Dx: Direct fecal smear, PCR (best) or fecal puch culture
Tx: Ronidazole but typically resolves without intervention
Relapses are common
35
What is prototheca and what does it cause?
- Toxic blue-green algae species in soil and sewage
CS: vomiting, diarrhea, ataxia, rapid death; chronic forms can see disseminated disease
Cats: cutaneous more common
Dogs: CNS, ocular, and Large bowel signs
36
How do you diagnose and treat prototheca and what is the prognosis?
Dx: culture, scraping, biopsy
Tx: Amphotericin B + Itraconazole
Prognosis: gave for disseminated and guarded for cutaneous
37
What are the pathogenic bacteria of the large intestine?
Campylobacter and clostridium
38
What clinical signs does campylobacter cause in the large intestine and how is it diagnosed?
CS: acute or chronic colitis with large bowel signs, pyrexia, anorexia
Dx: Culture and direct fecal smear
39
How is campylobacter diagnosed and what is the prognosis?
Tx: if healthy carrier tx isn't necessary, erythromycin and tylosin for ill pets
Prognosis: good
40
What are the clinical signs of clostridium difficile?
Large bowel diarrhea
May only be a contributing factor, not a primary cause
41
How do you diagnose and treat C. diff and what is the prognosis?
Dx: Overabundence on fecal smear, PCR/ELISA for toxins, culture
Tx: metronidazole
Prognosis: Good
42
Clostridium perfringens, all the things.
- High prevalence in normal pets
- Consider toxigenic culture to support d
- Metronidazole or tylosin for tx
- Theoretic zoonosis
43
Does inflammatory colonic disease present as an acute or chronic condition?
Chronic large intestinal signs for which no other cause can be found and fails to respond to empiric therapy
44
What will you find on histopath of an animal with inflammatory colonic disease?
Mucosal changes including inflammatory infiltrate
45
What diet trials can be attempted in colitis patients?
- Hydrolyzed or novel antigen
- Low residue (prolonged time)
- High fiber or addition of fiber
- Prebiotic supplementation
46
What is typically given as a prebiotic in colitis patients?
Fermentable fibers able to be used an an energy source for intestinal bacteria
- Beet pulp
- Psyllium husks
- Fructooligosaccharides
47
What are some fiber responsive diseases of the colon?
Chronic diarrhea without any apparent pathogens, infection, inflammation, neoplasia
Responsive to highly digestible diet with soluble fiber or fiber supplementation
48
What are fiber responsive diseases similar to in the small intestine?
Minimal change enteropathy
49
What antibiotics are typically used for large bowel diseases?
Metronidazole and tylosin
50
What is the typical cinical summary of colitis patients?
- Middle aged to older patients
- CS: large bowel diarrhea with occasional weight loss
- PE: good body condition, some thickening of intestine, may have mass lesions or pain on rectal
51
Patients with colitis typically have a good body condition unless they have what processes?
- Concurrent small intestinal disease
- Histiocytic ulcerative colitis
- Inappetence
52
What are the minimum database diagnostics for an animal with colitis?
CBC, CHEM, UA
Fecal
Imaging
53
What may colonoscopy show?
- Inflammatory bowel disease
- Histiocytic ulcerative colitis
- Neoplasia (polyps as well)
- Fibrosing structures
- Fungal plaques or granulomas
54
What are the clinical signs of histiocytic ulcerative colitis?
Tenesmus, mucoid diarrhea, hematochezia, weight loss, decreased appetite
55
What are the US, histo, and biopsy/culture results of a patient with granulomatous/HU colitis?
US: diffusely or segmetally thickened colonic wall or normal
Histopath: Macrophage infiltration of the mucosa, PAS positive
Biopsy/culture: FISH positive
56
T/F: HUC is treated with immunosuppressive drugs.
FALSE- do not use immune suppression
Baytril long term pending resolution of clinical signs
57
What is the issue with resistance and HUC?
Stopping baytril early will create resistance and a poor prognosis
Animals that do not respond to therapy may already have resistance
58
T/F: Most neoplasms of the large intestine are benign polyps.
False- most are malignant but benign polyps do occur
59
What neoplasms occur in the large intestine and rectum?
Adenocarcinoma, lymphosarcoma, stromal tumors, leiomyosarcoma (cecum), firbosarcoma, neurofibrosarcoma, ganglioneuroma, plasmacytoma, mast cell
60
What is the percentage of cases that have palpable neoplasms in dogs and cats?
Dogs- 60-80%
| Cats- 50%
61
What tests can be done to find/ classify large intestinal neoplasia?
- Colonoscopy
- Colon/rectal scrape and cytology
- Blind biopsy
- US guided aspirate
- Surgical biopsy (avoid cutting into colon)
62
What are come causes of colonic obstruction?
- Neoplasia or polyps
- Fibrosing strictures
- Fungal plaques or granulomas
- Foreign bodies
- Inflammatory disease
- Intussussceptions
- Constipation and obstipation
63
What is the most common type of colonic intussusception?
Ileocolic
Can have cecocolic, cecal inversion, ileocecal, and colonic as well
64
How do you tell the difference between a prolapse and an intussuseption?
Prolapse- should not be able to pass a probe at the mucosal junction
Protruding intussusception- will be able to pass a probe into the rectum
65
Which small animal species is more likely to present with chronic constipation?
Cats
66
What are some conditions that can lead to constipation?
- Dehydration and associated diseases
- Obesity
- Hypokalemia, hypercalcemia
- Environmental/behavioral issues
- Inflammation
- Mechanical obstruction
- Neuromuscular dysfunction
67
What is the difference between constipation, obstipation, and megacolon?
Constipation: infrequent and/or difficult impaction of feces, is not a permanent loss of function, mild to moderate dilation
Obstipation: intractable constipation refractory to cure or control, implies loss of function
Mega colon: severe dilation of hypertrophy of the colon, end stage of colonic dysfunction, can be secondary to obstructive lesion and may be reversible if caught early
68
What type of animals are more likely affected with megacolon?
Middle aged male cats most commonly
69
What are the clinical signs/presenting concerns of a constipated animal?
- Reduced, painful, or absent fecal production
- Multiple unproductive attempts at defecation
- Prolonged litterbox use
- Vocalization
- Vomiting (cats)
70
What are some physical exam findings on a constipated animal?
- Normal appearance
- Dehydration
- Weak
- Abdominal pain and positive palpation
Rectal: may have lyphadenopathy, mass lesions, strictures, pelvic narrowing
71
What should you look for on the clin path of a constipated animal?
Causes of dehydration and electrolyte imbalances
72
Why are radiographs useful in assessing a constipated patient?
- Assess severity
| - Point towards structural causes
73
Do we typically use colonoscoy and biopsy in the constipated patient?
Rarely, may need to for recurrent cases or to look for strictures and intraluminal masses
Biopsy to confirm congenital aganglionic megacolon in cats
74
How do you treat a constipated cat?
- Laxatives
- Prokinetic drugs
- Diet modification
- Enemas
- Surgery if recurrent
May require hospitalization depending on severity and chronicity
75
What are the different types of laxatives?
1. Emmoillent- increased lipid and decreased water absorption
2. Bulk forming
3. Lubricant- prevention of water reabsorbtion
4. Hyperosmotic- stimulates colonic cectreiton and propulsive motility
5. Stimulant- Increases propulsive motility
76
What is an emoillent laxatine?
Dicotyl sodium sulfosuccinate
77
What are bulk forming laxatives?
Psyllium, wheat bran, pumpkin
78
What are lubricant laxatives?
Mineral oil or white petroleum
79
What are hyper osmotic laxatives?
Magnesium salts or polyethylene glycol
80
What are stimulant laxatives
Prokinetic drugs
Cisapride
81
What can be used as a rectal suppository laxative?
- Glycerine
- DSS
- Bisacdyl
82
What do you use for enemas to disimpact an animal?
Warm water and lube via a red rubber catheter per rectum
83
What kind of enema do you never want to give and why?
Fleet enema (human drug) or anything with sodium phosphate as they can lead to severe electrolyte disturbances
84
What are two drugs that are helpful in constipated cats?
Miralaxx and lactulose
85
What is a concern when administering enemas?
Fluid overload
Especially a concern in small animals
86
What is the procedure for manual deobstipation?
- General anesthesia
- Warm water with lube or saline enema
- Manual external manipulation "milking"
Must be prepped with hydration, antibiotics, and enemas and may have to stage over several days
87
What surgery can you perform on an obstipated patient and when is it indicated?
Subtotal colectomy
Only if refractory to meds
Has a good prognosis but may have diarrhea for a significant time post op
