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Types of Diverticular Disease

1. Diverticulosis
Diverticula present

2. Diverticulitis
Inflamed diverticula
May cause potentially fatal obstruction, infection or hemorrhage


Most common sites: Diverticula

Sigmoid colon
Descending colon


Contributing factors: Diverticular Disease

1. Diminished colon motility & increased intraluminal pressure
2. Low fiber diet
3. Connective tissue disorders
-Marfan Syndrome


Pathophysiology: Diverticular Disease

Diverticula result from high intraluminal pressure on area of weakness in GI wall where blood vessels enter

Diet may be contributing factor

Insufficient fiber reduces fecal residue --> narrows bowel lumen --> leads to high intra-luminal pressure during defecation


Signs & Sx’s Diverticulosis

Most asymptomatic

Some pts may have nonspecific complaints:
-Chronic constipation
-Abd pain
-Fluctuating bowel habits

Exam usually unremarkable


Diagnostic Studies: Diverticulosis

No imaging needed for uncomplicated disease

Diverticula best seen on barium enema or CT abd & pelvis w/contrast

Colonoscopy less sensitive in detecting diverticula


Treatment: Diverticulosis

High fiber diet or fiber supplements reduce likelihood of complications


General Characteristics: Diverticulitis

Defined as inflammation of diverticula caused by obstructing matter

Patients with diverticulosis are at risk of developing diverticulitis


Pathophysiology: Diverticulitis

Undigested food & bacteria accumulate in diverticular sac

Hard mass cuts off blood supply to thin walls of sac --> increased risk of infection

Untreated --> increased risk of perforation


Signs & Sx’s Diverticulitis

1. Abd pain
-Sudden onset
-Usually LLQ (site of tics)
2. +/- fever
3. Diarrhea OR constipation
4. N / V
5. +/- distention
6. Palpable tenderness
- +/- mass in affected area
- Guarding
- +/- rebound tenderness
7. DRE may be tender


Differential Dx: Diverticulitis

1. Perforated colon CA
2. Crohn’s Disease
3. Appendicitis
4. Ischemic colitis
5. C. Difficile colitis
6. GYN disorders
-Ectopic pregnancy
-Ovarian cyst
-Ovarian torsion


Diagnostic Studies: Diverticulitis

1. Guaiac (+) stool common
2. Mild-mod leukocytosis
3. CT Abd/pelvis
-Recommended in pts who do not respond to empiric therapy after 2-4 days
-Evaluates extent of disease and R/O underlying colon CA
4. Barium enema & colonoscopy should be avoided during acute phase due to risk of perforation & peritonitis
5. CT Abd/pelvis
-Colonic diverticuli & wall thickening
-Peri-colic fat infiltration
-Abscess formation
-Extraluminal air
6. Colonoscopy or BE done ≈ 6 weeks later
-R/O IBD or colon CA
-Evaluate extent of tics/obstruction risk


Treatment: Diverticulitis

1. Mild diverticulitis
a. Clear liquid / BRAT / Low residue diet
b. Add antibx if persistent
-Broad spectrum antibiotics x 7-10 days
(Fluoroquinolones/Ciprofloxin (Cipro) 500 mg po bid
Metronidazole (Flagyl) 500 mg po tid)

2. Moderate diverticulitis
a. Hospitalization & NPO
b. IV antibiotics x 5-7 days [gram (+), gram (-) & anaerobic coverage]
(Cefotaxime (Claforan) or piperacillin (Zosyn)
Metronidazole (Flagyl) + ceftriaxone (Rocephin))
3. Bowel rest (NPO)
4. Analgesia
5. NG tube if ileus develops


Surgery: Diverticulitis

1. Severe diverticulitis or unresponsive to Tx
a. Done if:
-Large abscess
2. Two stage procedure:
a. Diseased colon resected, proximal colon brought out to form temp colostomy; distal stump closed
b. 3-6 months later, after inflammation subsides, colon can be reconnected electively


General Characteristics: Irritable Bowel Syndrome

Functional disorder without known pathology

Most common cause of chronic or recurrent abd pain in US

Intermittent, lifelong problem

F > M


Pathophysiology: IBS

1. Current evidence suggests combination of:
-Altered motility
-Hypersensitivity to intestinal distention
-Psychological distress


Sx’s: IBS

1. Abd pain
a. Hypogastrium
b. LLQ
2. Pain worsened w/ food & relieved w/ defecation
3. Postprandial urgency
4. Bowel distention
a. Accumulation of gas
5. Constipation, diarrhea or both
6. PE Normal


Differential Diagnosis: IBS

Lactose intolerance
Chronic pancreatitis
Intestinal obstruction
Pancreatic CA
Stomach cancer
Celiac disease


Diagnostic Studies: IBS

1. Dx of exclusion
2. Stool for O&P, fecal WBC’s, blood, culture
a. R/O infection
3. CT w/contrast/Ba enema
a. R/O obstructing mass, pancreatic cancer
4. Endoscopy
a. R/O celiac disease, stomach cancer


Treatment: IBS

1. Reassurance
2. Strong provider-patient relationship
3. Avoidance of known triggers
4. High fiber diet
5. Bulking agents
-Psyllium / Metamucil
-Methylcellulose / Citrucel
-Calcium Polycarbophil /FiberCon

6. Anti-diarrheal meds
a. Opioid Agonists
b. Activate opioid receptors in GI smooth muscle  inhibits AcH release --> inhibits peristalsis
c. Includes:
-Loperamide (Immodium) – opioid analogue
-Diphenoxylate (Lomotil)

7. Anti-constipation meds
a. Increase intestinal fluid secretion & motility
-Lubiprostone (Amitiza)
-Linaclotide (Linzess)

8. Prokinetic meds
a. Stimulates motility of upper GI tract w/out stimulating gastric, biliary or pancreatic secretions
-Metochlopramide (Reglan) 10 mg po 30 min ac & hs

9. Antidepressants/antidiarrheal (females only)
a. Used in severe cases only, restricted use
b. Serotonin (5HT3) receptor agonist
c. Slows down GI motility
-Alosetron (Lotronex)


Constipation: General Characteristics

Normal bowel function ranges from 3 stools/day to 3 stools/week

Decrease in stool volume & increase in stool firmness accompanied by straining

Patients > 50 yr with new onset constipation should be evaluated for colon cancer


Etiology: Constipation

1. Primary constipation
a. Anal stricture
b. Rectocele
c. Rectal prolapse
2. Secondary constipation
a. Systemic disease
-Hypothyroidism, DM, hypercalcemia
b. Medications
-Opioids, diuretics, anticholinergics, Ca & Fe supplements
c. Obstructing colonic lesions


Work - Up: Constipation

1. Complete Hx & PE is essential, including:
-Stool guaiac

2. Diagnostic Studies
-Ca, glucose


Treatment: Constipation

1. Increase fiber
-10-20 gm daily
2. Increase fluid intake
-1.5 – 2 L / day
3. Increase activity
4. If constipation lasts > 2 weeks or if constipation refractory to above measures, further investigation to detect etiology


Colon Polyps: General Characteristics

1. Colon polyps are discrete mass lesions that protrude into intestinal lumen
a. Can be benign or malignant

2. Removal of colon polyps can reduce occurrence of colon cancer

3. Familial polyposis syndrome is a genetic predisposition to multiple colon polyps
a. High risk colon cancer


Types of Polyps

1. Mucosal neoplastic (adenomatous)
a. Most common type
b. 95% adenocarcinoma of colon arise from these polyps

2. Mucosal non-neoplastic (hyperplastic)
a. Non malignant

3. Submucosa
a. Lipomas
b. Lymphoid aggregates


Prevention: Colon Polyps

1. Diet high in fruits, vegetables & fiber
2. Low fat diet
3. Limit ETOH intake
4. Avoid tobacco
5. Anti-oxidant vitamins
a. A, C, E, beta carotene
a. Due to risks asst w/long term use, ASA not recommended in pts w/polyps unless there are other medical indications
b. Reduces number of recurrent adenomas at 1-3 yr
-Low dose ASA 81 mg PO qd
-Celecoxib (Celebrex) 400 mg PO bid


Risk Factors: Colon Polyps

Diet rich in fats and red meats
(+) FH


Signs & Sx’s: Colon Polyps

Polyps generally asymptomatic

May be asst with rectal bleeding & iron deficiency anemia


Diagnostic Studies: Colon Polyps

1. Guaiac (+) stool common
2. Imaging studies:
a. Barium enema
-Not used much today
b. Colonoscopy
- Diagnostic study of choice for localizing & identifying (Bx) polyps
(Histologic evaluation of polyps
Virtual colonoscopy/ pill camera)

3. Family members of pts w/ familial polyposis should be evaluated q 1-2 yr beginning at 10-12 yr of age


Treatment: Colon Polyps

1. Colonoscopic polypectomy

2. Post-polypectomy Surveillance
a. Colonoscopy w/in 3-5 yr after initial exam
-Adenomas found in 30-40% of pt after initial (+) exam
-Colonoscopy in 5-10 yr after first normal post-polypectomy exam
3. Patients with 3-10 adenomatous polyps or polyp > 1 cm
a. Colonoscopy in 3 yr


Familial Adenomatous Polyposis

1. Inherited condition characterized by early development of hundreds to thousands of colonic adenomatous polyps & adenocarcinoma

2. Genetic testing confirms mutation of:
-APC gene (90%)
-MYH gene (8%)

3. Prophylactic colectomy recommended to prevent otherwise inevitable colon cancer
-Usually before age 20 yr


Colorectal Cancer: General Characteristics

1. Almost all colorectal cancers are adenocarcinomas
a. Form bulky masses

2. Majority of colorectal cancers arise from malignant transformation of adenomatous polyps


Colorectal Cancer: Risk Factors

1. Aging
a. 90% cases > 50 yr
2. (+) FH
3. IBD
a. Cumulative risk 5-10% after 20 yr & 20% after 30 years
4. High fat diet
a. > 1 drink/day
6. M > F
7. B > W
8. Tobacco use
9. Obesity
10. Lack of physical activity


Colorectal Cancer: FH Risk Factors

Pts w/one 1st degree relative w/colorectal CA have increased risk 2x that of general population

Risk is 4x greater if relative was diagnosed < 45 yr

20-30% lifetime risk if two 1st degree relatives have colon CA


Colorectal Cancer: Sx’s & Tumor Location

1. Right sided colon CA
a. Fatigue/weakness

2. Left sided colon CA
a. Fatigue/weakness
b. Colicky abd pain
c. Change in bowel habits
d. Obstructing lesion

3. Rectal CA
a. Fatigue/weakness
b. Tenesmus
c. Urgency
d. Recurrent hematochezia


Colorectal Cancer: Sxs

Physical exam may be normal

(+) guaiac common

Palpable mass
-Suggests advanced disease

-Suggests metastatic spread


Colorectal Cancer: Differential Dx

Diverticular disease
Ischemic colitis


Colorectal Cancer: Diagnostic Studies

1. CBC
-Iron Def Anemia
2. Elevated LFT’s
-Metastatic Dz
3. Carcinoembryonic Ag (CEA)
-Tumor marker
-Pre-op level > 5 ng/ml poor prognosis
4. Colonoscopy
-Diagnostic procedure of choice
-Provides histologic Dx


Colorectal Cancer: Imaging

1. CT Chest/Abd/Pelvis
a. Demonstrates distant mets

2. Ultrasound liver
a. More accurate than CT for liver mets

3. Pelvic MRI
a. Rectal cancer
-Determines depth of penetration of CA through rectal wall


Colorectal Cancer: Staging

Stage 0
-Polyp or lesion at innermost lining of the colon
Stage 1
-Beyond innermost lining of colon to second & third layers 
Stage II
-Extends thru muscular wall of colon, but not in nodes
Stage III
-Extends outside colon to ≥ lymph node
Stage IV
-Extends outside the colon to distant organs (liver or the lungs)


Colorectal Cancer: Treatment

Resection of tumor

Regional lymph node dissection
-Minimum 12 nodes
-Determines staging & adjunctive chemoTx

Rectal CA
-Pre-op chemo-radiation followed by surgery

Patients should be evaluated q 3-6 months for 3-5 yrs:
-Repeat colonoscopy 1 yr post-op; then q 3-5 yr


Screening Recommendations for Colorectal CA

1. Screening colonoscopy
a. USPTF & ACS recommends start screening at age 50 yr
b. If 1st degree relative with colon CA, begin screening at 40 yr OR at age 10 yr younger than age at which relative was Dx’d
-Single 1st degree relative w/ CA > 60 yrs, begin screening at age 40 & screen q 10 yr
-Single 1st degree relative w/CA < 60 yrs, OR 2 1st degree relatives, begin screening at 40 yr or younger; screen q 5 yr


Colorectal Cancer: Screening Methods

1. Stool Guaiac (FOBT)
2. Flexible sigmoidoscopy
a. Detects approx 65% advanced neoplasms
b. Does not examine proximal colon
3. Colonoscopy
a. Permits exam of entire colon
b. Preferred
-Allows detection and removal polyps
c. Although most sensitive test, not infallible
4. Barium Enema
a. Rarely used today


Toxic Megacolon: General Characteristics

1. Extreme dilatation & immobility of colon
2. True emergency!!
3. Hirschsprung’s Dz
a. Congenital aganglionosis of colon
b. Leads to functional obstruction in newborn
4. In adults, toxic megacolon occurs as a complication of:
a. UC
b. Crohn’s Disease
c. Pseudomembranous colitis
d. Infections
-Shigella, Campylobacter, C. Difficile


Toxic Megacolon: Signs & Sx’s

1. Fever
a. Hypothermia if sepsis
2. Prostration
3. Severe cramps
4. Abd distention
5. Rigid abdomen
6. Localized or diffuse rebound tenderness
7. Tachycardia
8. Dehydration


Toxic Megacolon: Diagnostic Studies

1. CBC
a. Leukocytosis most common
b. If sepsis→ leukopenia
2. BMP
3. KUB
a. Colonic dilatation


Toxic Megacolon: Treatment Goals

Reduce colonic distention to prevent perforation

Correct fluid and electrolyte disturbances

Treat toxemia & precipitating factors


Toxic Megacolon: Treatment

1. Decompression of colon within 24 hr
a. NG tube, long intestinal tubes
b. If unable, then:
-Subtotal colectomy w/ ileostomy
2. attention to fluid & electrolyte balance
a. High risk for septic shock
3. Corticosteroids if resulted from active IBD
4. Antibiotics given to prevent sepsis
a. Ampicillin, gentamicin, & metronidazole (or equivalent)
5. D/C possible triggers: narcotics, antidiarrheals, & anticholinergics
6. Risk of death is high 2* perforation, sepsis, shock