bowel diseases: large intestine

Question 1

Diseases of the Colon and Rectum

Answer 1

Irritable bowel syndrome
Antibiotic-associated colitis
Inflammatory Bowel Disease:
Crohn disease
Ulcerative colitis (UC)

Question 2

Diseases of the Colon and Rectum 2

Answer 2

Diverticular disease
Diverticulosis
Diverticulitis
Polyps
Familial adenomatous polyposis
Hamartomatous polyposis syndromes
Lynch syndrome

Question 3

IBS

Answer 3

An idiopathic clinical entity characterized by chronic (more than 6 months) abdominal pain or discomfort that occurs in association with altered bowel habits
Symptoms may be continuous or intermittent

Question 4

Definition of irritable bowel syndrome is abdominal discomfort or pain that has two of the following three features:

Answer 4

• Relieved with defecation
• Onset associated with a change in frequency of stool
• Onset associated with a change in form (appearance) of stool

Question 5

IBS: Other symptoms supporting the diagnosis include ??

Answer 5

abnormal stool frequency; abnormal stool form (lumpy or hard; loose or watery); abnormal stool passage (straining, urgency, or feeling of incomplete evacuation); passage of mucus; and bloating or a feeling of abdominal distention

Question 6

IBS epi

Answer 6

Patients may have other somatic or psychological complaints such as dyspepsia, heartburn, chest pain, headaches, fatigue, myalgias, urologic dysfunction, gynecologic symptoms, anxiety, or depression
Common problem presenting to both gastroenterologists and PCPs
-Up to 10% of the adult population have symptoms compatible with the diagnosis, but most never seek medical attention
-Approximately two-thirds of patients with irritable bowel syndrome are women.

Question 7

IBS Pathophysiologic mechanisms have been identified:

Answer 7

Abnormal Motility
Visceral Hypersensitivity
Enteric Infection
*Psychosocial Abnormalities

Question 8

IBS presentation

Answer 8

Chronic condition
*Diagnosis of exclusion
Symptoms usually begin in the late teens to twenties
Abdominal pain usually is intermittent, crampy, and in the lower abdominal region

Question 9

Patients with irritable bowel syndrome may be classified into one of three categories based on the predominant bowel habit:

Answer 9

• Irritable bowel syndrome with diarrhea
• Irritable bowel syndrome with constipation
• *Irritable bowel syndrome with mixed constipation and diarrhea

Question 10

“Alarm symptoms” that suggest a diagnosis other than irritable bowel syndrome and warrant further investigation

Answer 10

Acute onset of symptoms
Nocturnal diarrhea, severe constipation or diarrhea, hematochezia, weight loss, and fever
Family history of cancer, inflammatory bowel disease, or celiac disease
-dx of exclusion

Question 11

IBS s/s

Answer 11

The physical examination usually is normal

Abdominal tenderness, especially in the lower abdomen, is common but not pronounced.

Question 12

IBS labs

Answer 12

The use of routine blood tests (complete blood count, chemistry panel, serum albumin, thyroid function tests, erythrocyte sedimentation rate) is unnecessary in most patients
Stool specimen examinations for ova and parasites should be obtained only in patients with increased likelihood of infection
Routine sigmoidoscopy or colonoscopy is not recommended in young patients with symptoms of irritable bowel syndrome without alarm symptoms but should be considered in patients who do not improve with conservative management

Question 13

IBS labs2

Answer 13

In all patients age 50 years or older who have not had a previous evaluation, colonoscopy should be obtained to exclude malignancy
When colonoscopy is performed, random mucosal biopsies should be obtained to look for evidence of microscopic colitis
-In patients with IBS with diarrhea, serologic tests for celiac disease should be performed
-Routine testing for bacterial overgrowth with hydrogen breath tests are not recommended
(labs not usually helpful)

Question 14

IBS tx

Answer 14

-General measures: Reassurance, education, and support
-Dietary Therapy: intolerances
-Pharmacologic Measures: Antispasmodic agents, Antidiarrheal agents,
Anticonstipation agents
-Psychotropic agents: SSRIs
-Nonabsorbable antibiotics, Probiotics
-Psychological Therapies: Cognitive behavioral therapies, relaxation techniques, hypnotherapy

Question 15

Antibiotic-Associated Colitis

Answer 15

(C. diff is a subset) Common clinical occurrence
Occurs during the period of antibiotic exposure, is dose related, and resolves spontaneously after discontinuation of the antibiotic
In most cases, this diarrhea is mild, self-limited, and does not require any specific laboratory evaluation or treatment

Question 16

Antibiotic-Associated Colitis labs

Answer 16

Stool examination usually reveals no fecal leukocytes, and stool cultures reveal no pathogens

• Although C difficile is identified in the stool of 15–25% of cases of antibiotic-associated diarrhea, it is also identified in 5–10% of patients treated with antibiotics who do not have diarrhea
• Most cases of abx-associated diarrhea are due to changes in colonic bacterial fermentation of carbohydrates and are not due to C difficile

Question 17

Antibiotic-Associated Colitis epi

Answer 17

• C difficile colitis is the major cause of diarrhea in patients hospitalized for more than 3 days, affecting 22 patients of every 1000
• Fastidious hand washing and use of disposable gloves are helpful in minimizing transmission
• C difficile is acquired in approximately 20% of hospitalized patients, most of whom have received antibiotics difficile colitis will develop in approximately one-third of infected patients

Question 18

Antibiotic-Associated Colitis tx

Answer 18

Prophylactic administration of the probiotics who are receiving antibiotics reduced the incidence of C difficile–associated diarrhea
-Symptoms usually begin during or shortly after antibiotic therapy but may be delayed for up to 8 weeks

Question 19

Antibiotic-Associated Colitis presentation

Answer 19

• Most patients report mild to moderate greenish, foul-smelling watery diarrhea 5–15 times per day with lower abdominal cramps
• Normal abdominal exam or mild left lower quadrant tenderness
• Colitis is most severe in the distal colon and rectum
• Over half of hospitalized patients diagnosed with C diff colitis have a white blood count greater than 15,000/mcL
• Severe or fulminant disease occurs in 10–15% of patients

Question 20

Antibiotic-Associated Colitis: labs/imaging

Answer 20

Stool studies: Rapid enzyme immunoassays (EIAs)
Nucleic acid amplication tests (PCR assays)

Flexible sigmoidoscopy: Not needed with typical symptoms and positive stool toxin assay
Can see true pseudomembranous colitis in severe cases

Imaging studies:
For severe disease
Abnormal radiographs or noncontrast abdominal CT

Question 21

Antibiotic-Associated Colitis tx

Answer 21

Antibiotic therapy should be discontinued

• Start metronidazole, PO vancomycin, or fidaxomicin (PO flagel for mild cases)
• For patients with severe disease, PO vancomycin and IV metronidazole
• Early sx consult is recommended for all patients with severe or fulminant disease
• Total abdominal colectomy or loop ileostomy with colonic lavage may be required in patients with toxic megacolon, perforation, sepsis, or hemorrhage

Question 22

Antibiotic-Associated Colitis: Treatment of relapse

Answer 22

• Up to 25% of patients have a relapse of diarrhea from C diff within 1-2 weeks after stopping initial therapy
• Most relapses respond promptly to a second course of the same regimen used for the initial episode
• For patients with two relapses, a 7-week tapering regimen of vancomycin is recommended
• Probiotic therapy is recommended as adjunctive therapy in patients with relapsing disease

Question 23

For patients with 3+ relapses of Antibiotic-Associated Colitis, updated 2013 guidelines recommend consideration of an ??

Answer 23

installation of a suspension of fecal bacteria from a healthy donor “fecal transplantation” into the terminal ileum or proximal colon (by colonoscopy) or into the duodenum and jejunum (by nasoenteric tube)

Question 24

IBD: Know the differences between Crohn disease and Ulcerative Colitis (UC)

Answer 24

slide 19, first aid 362
For Crohn, think of a FAT GRANny and an old crone SKIPping down a COBBLESTONE road away from the wRECk (rectal sparing).

Ulcerative colitis causes ULCCCERS: Ulcers
Large intestine
Continuous, Colorectal carcinoma, Crypt abscesses
Extends proximally Red diarrhea Sclerosing cholangitis

Question 25

Crohn Disease (worse of the 2)

Answer 25

One-third of cases of Crohn disease involve the small bowel only, most commonly the terminal ileum (terminal ileitis, B12 def)
-Half of all cases involve the small bowel and colon, most often the terminal ileum and adjacent proximal ascending colon (ileocolitis)
-In 20% of cases, the colon alone is affected
One-third of patients have associated perianal disease
-Less than 5% patients have symptomatic involvement of the upper intestinal tract

Question 26

Unlike ulcerative colitis, Crohn disease is a ??

?? is strongly associated with the development of Crohn disease, resistance to medical therapy, and early disease relapse

Answer 26

transmural process that can result in mucosal inflammation and ulceration, stricturing, fistula development, and abscess formation

Cigarette smoking (in UC get better if smoke!)

Question 27

Crohn disease May present with a variety of symptoms and signs

Physical examination should focus on the ??

Answer 27

History of fevers, general sense of well-being, weight loss, the presence of abdominal pain, the number of liquid bowel movements per day, and prior surgical resections

patient’s temperature, weight, and nutritional status, the presence of abdominal tenderness or an abdominal mass, rectal examination, and extraintestinal manifestations

Question 28

Crohn’s: 5 common presentations (can overlap)

Answer 28

Chronic inflammatory disease
Intestinal obstruction
Penetrating disease and fistulae
Perianal disease
Extraintestinal disease (arthralgia, pyoderma gangrenosum, slide 27)

Question 29

Crohn’s labs

Answer 29

Poor correlation between laboratory studies and the patient’s clinical picture

• Laboratory values may reflect inflammatory activity or nutritional complications of disease
• A complete blood count and serum albumin should be obtained in all patients
• Anemia may reflect chronic inflammation, mucosal blood loss, iron deficiency, or vitamin B12 (mixed picture) malabsorption secondary to terminal ileal inflammation or resection
• Leukocytosis may reflect inflammation or abscess formation or may be secondary to corticosteroid therapy

Question 30

Crohn’s labs 2

Answer 30

Hypoalbuminemia may be due to intestinal protein loss (protein-losing enteropathy), malabsorption, bacterial overgrowth, or chronic inflammation

• The sedimentation rate or C-reactive protein level is elevated in many patients during active inflammation
• Autoantibodies to P-ANCA* as well as antibodies to the yeast Saccharomyces cerevisiae

Question 31

Crohn’s imaging

Answer 31

Colonoscopy usually is performed first to evaluate the colon and terminal ileum and to obtain mucosal biopsies
Typical endoscopic findings include aphthoid, linear or stellate ulcers, strictures, and segmental involvement with areas of normal-appearing mucosa adjacent to inflamed mucosa

Question 32

Crohn’s imaging 2

Answer 32

CT or MR enterography or a barium upper gastrointestinal series with small bowel follow-through often is obtained in patients with suspected small bowel involvement
Suggestive findings include ulcerations, strictures, and fistulas; in addition, CT or MR enterography may identify bowel wall thickening and vascularity, mucosal enhancement, and fat stranding

Question 33

Crohn’s complications

Answer 33

Abscess
Obstruction
Abdominal and Rectovaginal Fistulas
Perianal Disease
Colon carcinoma
Hemorrhage (unusual, more in UC))
Malabsorption
(more hemorrhage in US)

Question 34

Crohn’s tx

Answer 34

Nutrition, Diet, Enteral Therapy, TPN
Symptomatic Medications:
Antidiarrheal in non-severe cases

Question 35

Crohn’s tx 2

Answer 35

Specific Drug Therapy:
5-Aminosalicyclic acid (5-ASA) agents
Antibiotics, Corticosteroids (reserved for acute flares, do not dec. morbidity, mortality)
Immunomodulators: Azathioprine, mercaptopurine, or methotrexate
Anti-TNF therapies (life-long)
Anti-intergrins

Question 36

Surgery for Crohn’s

Answer 36

Over 50% of pts will require at least one surgical procedure
-Main indications for surgery are intractability to medical therapy, intra-abdominal abscess, massive bleeding, symptomatic refractory internal or perianal fistulas, and intestinal obstruction

Question 37

UC ??

Answer 37

is an idiopathic inflammatory condition that involves the mucosal surface of the colon, resulting in diffuse friability and erosions with bleeding

• Approximately one-third of patients have disease confined to the rectosigmoid region (proctosigmoiditis)
• One-third have disease that extends to the splenic flexure (left-sided colitis)
• One-third have disease that extends more proximally (extensive colitis)
• The disease is characterized by periods of symptomatic flare-ups and remissions

Question 38

UC and smoking

Answer 38

Ulcerative colitis is more common in nonsmokers and former smokers
Disease severity may be lower in active smokers and may worsen in patients who stop smoking

Question 39

UC presentation

Answer 39

Presentation is highly variable
Bloody diarrhea is the hallmark
Severe based on stool frequency, the presence and amount of rectal bleeding, cramps, abdominal pain, fecal urgency, and tenesmus
Vitals are key (tachy, Hgb drops)
Look for tenderness and evidence of peritoneal inflammation
Red blood may be present on digital rectal examination.

Question 40

UC slide 40

Answer 40

sev:
>6 stools (typ. bloody), >100 bpm, HCT less than 30, more than 10% weight loss, greater than 100 temp, ESR>30, albumin less than 3

Question 41

UC: mild-mod colitis tx

Answer 41

5-ASA agents
Corticosteroids
Immunomodulating agents
Anti-integrin therapy
Probiotics

Question 42

UC: Severe and fulminant colitis tx

Answer 42

NPO
Corticosteroid therapy
Anti-TNF therapies
Cyclosporine
Surgical therapy! (take out colon: cured!)

Question 43

UC: Risk of Colon Cancer

Answer 43

Disease proximal to the rectum

• Colonoscopies are recommended every 1–2 years in patients with colitis, beginning 8 years after diagnosis*
• At colonoscopy, all adenoma-like polyps should be resected, when possible, and biopsies obtained of non-endoscopically resectable mass lesions

Question 44

Diverticulosis

Answer 44

Colonic diverticulosis increases with age, ranging from 5% in those under age 40, to 30% at age 60, to more than 50% over age 80 years in Western societies

• Most are asymptomatic, discovered incidentally at endoscopy or on barium enema
• Complications occur in less than 5%, including gastrointestinal bleeding and diverticulitis

Question 45

Diverticulosis 2

Answer 45

Colonic diverticula may vary in size from a few millimeters to several centimeters and in number from one to several dozen

• Almost all patients with diverticulosis have involvement in the sigmoid and descending colon
• Only 15% have proximal colonic disease

Question 46

diverticulosis etiology

Answer 46

For over 40 years, it has been believed that diverticulosis arises after many years of a diet deficient in fiber ** (reduce red meat, switch to low fat diet)
-May develop more commonly in the sigmoid because intraluminal pressures are highest in this region
-True etiology of diverticulosis is uncertain
The extent to which abnormal motility and hereditary factors contribute to diverticular disease is unknown

Question 47

Patients with ?? are also disposed to development of diverticulosis, including ??

Answer 47

abnormal connective tissue

Ehlers-Danlos syndrome, Marfan syndrome, and scleroderma

Question 48

diverticulosis presentation

Answer 48

More than 90% of patients with diverticulosis have uncomplicated disease and no specific symptoms
-In most, diverticulosis is an incidental finding detected during colonoscopic examination or barium enema examination
Some patients have nonspecific complaints of chronic constipation, abdominal pain, or fluctuating bowel habits

Question 49

diverticulosis PE and advice

Answer 49

Physical examination is usually normal but may reveal mild left lower quadrant tenderness with a thickened, palpable sigmoid and descending colon
-Pts in whom diverticulosis is discovered, especially patients with symptoms or a history of complicated disease, should be treated with a high-fiber diet or fiber supplements (drink lots of water with it)

Question 50

Diverticulitis

Answer 50

Perforation of a colonic diverticulum results in an intra-abdominal infection that may vary from microperforation (most common) with localized paracolic inflammation to macroperforation with either abscess or generalized peritonitis

Question 51

diverticulitis presentation

Answer 51

Constipation or loose stools may be present

• Nausea and vomiting are frequent
• Low-grade fever, left lower quadrant (LLQ) tenderness, and a palpable mass*

Question 52

diverticulitis: Mild symptoms and a presumptive diagnosis of diverticulitis, tx ??

Answer 52

empiric medical therapy is started without further imaging in the acute phase

Patients who respond to acute medical management should undergo complete colonic evaluation with colonoscopy or radiologic imaging after resolution of clinical symptoms to corroborate the diagnosis or exclude other disorders such as colonic neoplasms

Question 53

diverticulitis pts who do not improve rapidly after 2–4 days of empiric therapy and in those with severe disease, tx ??

Answer 53

CT scan of the abdomen is obtained to look for evidence of diverticulitis and determine its severity

Question 54

Endoscopy and colonography are contraindicated during the initial stages of an acute diverticulitis attack because of the risk of ?

Answer 54

free perforation

need to do later to check for colon cancer

Question 55

diverticulitis tx: Patients with mild symptoms and no peritoneal signs

Answer 55

may be managed initially as outpatients on a clear liquid diet (not done often)
Although broad-spectrum oral antibiotics with anaerobic activity commonly are prescribed (ciproflagil, etc.)
Symptomatic improvement usually occurs within 3 days, at which time the diet may be advanced
Once the acute episode has resolved, a high-fiber diet is often recommended
Patients with increasing pain, fever, or inability to tolerate oral fluids require hospitalization

Question 56

diverticulitis tx 2: Patients with severe diverticulitis

Answer 56

(high fevers, leukocytosis, or peritoneal signs) and patients who are elderly or immunosuppressed or who have serious comorbid disease require hospitalization acutely

• Patients should be given nothing by mouth and should receive intravenous fluids. If ileus is present, a nasogastric tube should be placed
• Intravenous antibiotics should be given to cover anaerobic and gram-negative bacteria

Question 57

diverticulitis sx

Answer 57

sx consult and repeat abd CT imaging should be obtained on all patients with severe disease or those who do not improve after 72 hours of medical management

• Patients with a localized abdominal abscess 4 cm in size or larger are usually treated urgently with a percutaneous catheter drain placed by an interventional radiologist
• Indications for emergent surgical management include generalized peritonitis, large undrainable abscesses, and clinical deterioration despite medical management and percutaneous drainage

Question 58

Polyps are discrete mass lesions that??

Answer 58

protrude into the intestinal lumen

Although most commonly sporadic, they may be inherited as part of a familial polyposis syndrome

Question 59

Polyps may be divided into four major pathologic groups

Answer 59

• Mucosal adenomatous polyps (tubular, tubulovillous, and villous)
• Mucosal serrated polyps (hyperplastic, sessile serrated polyps, and traditional serrated adenoma)
• Mucosal nonneoplastic polyps (juvenile polyps, hamartomas, inflammatory polyps)
• Submucosal lesions (lipomas, lymphoid aggregates, carcinoids, pneumatosis cystoides intestinalis)

Question 60

Familial Adenomatous Polyposis

Answer 60

Syndrome affecting 1:10,000 people and accounts for approximately 0.5% of colorectal cancer

• Classic form of FAP is characterized by the development of hundreds to thousands of colonic adenomatous polyps and a variety of extracolonic manifestations
• Approximately 90% have a mutation in the APC gene that is inherited in an autosomal dominant fashion

Question 61

Familial Adenomatous Polyposis complications

Answer 61

• Colorectal polyps develop by a mean age of 15 years and cancer at 40 years
• Unless prophylactic colectomy is performed, colorectal cancer is inevitable by age 50 years
• Development of a variety of other benign extraintestinal manifestations, including soft tissue tumors of the skin, desmoid tumors, osteomas, and congenital hypertrophy of the retinal pigment

Question 62

Familial Adenomatous Polyposis testing/tx

Answer 62

• Genetic counseling and testing should be offered to patients found to have multiple adenomatous polyps at endoscopy and to first-degree family members of patients with FAP
• Once dx w. FAP, complete proctocolectomy with ileoanal anastomosis or colectomy with ileorectal anastomosis is recommended, usually before age 20 years

Question 63

Hamartomatous Polyposis Syndromes

Answer 63

*Peutz-Jeghers syndrome
Familial juvenile polyposis
PTEN multiple hamartoma syndrome (Cowden disease)

Question 64

Peutz-Jeghers syndrome

Answer 64

Autosomal dominant condition characterized by hamartomatous polyps throughout the gastrointestinal tract as well as mucocutaneous pigmented macules on the lips, buccal mucosa, and skin

Question 65

Familial juvenile polyposis

Answer 65

Autosomal dominant and is characterized by several juvenile hamartomatous polyps located most commonly in the colon

Question 66

PTEN multiple hamartoma syndrome (Cowden disease)

Answer 66

Hamartomatous polyps and lipomas throughout the gastrointestinal tract, trichilemmomas, and cerebellar lesions

Question 67

Lynch syndrome (also known as hereditary nonpolyposis colon cancer [HNPCC]) is an ??

Answer 67

autosomal dominant condition in which there is a markedly increased risk of developing colorectal cancer as well as a host of other cancers, including endometrial, ovarian, renal or vesical, hepatobiliary, gastric, and small intestinal cancers

Question 68

Lynch syndrome epi

Answer 68

Estimated to account for up to 3% of all colorectal cancers
Affected individuals have a 22–75% lifetime risk of developing colorectal carcinoma and a 30–60% lifetime risk of endometrial cancer, depending on the affected gene

Question 69

Lynch Syndrome screening

Answer 69

A thorough family cancer history is essential to identify families that may be affected with Lynch syndrome so that appropriate genetic and colonoscopic screening can be offered
If genetic testing documents a Lynch syndrome gene mutation, affected relatives should be screened with colonoscopy every 1–2 years beginning at age 25 (or at age 5 years younger than the age at diagnosis of the youngest affected family member)
If cancer is found, subtotal colectomy with ileorectal anastomosis (followed by annual surveillance of the rectal stump) should be performed

Question 70

Lynch Syndrome screening 2

Answer 70

-Women should undergo screening for endometrial and ovarian cancer beginning at age 30–35 years with pelvic examination, transvaginal ultrasound, and endometrial sampling
Prophylactic hysterectomy and oophorectomy is recommended to women at age 40 or once they have finished childbearing
Screening for gastric cancer with upper endoscopy should be considered every 2–3 years beginning at age 30–35 years