1. Colon, Rectum, and Anus
Chapter 15

2. Introduction Anatomy Diverticular Disease Polyps and Carcinoma
Ulcerative Colitis and Crohn’s Disease
Colonic Obstruction
Hemorrhoids
Perianal infections
Anal malignancy

3. Anatomy

5. Diverticular Disease Common colonic diverticula are false diverticula
Only consist of mucosa and submucosa that protrude through the colonic wall
Occur on the mesenteric side of the colon where the arterioles penetrate the muscularis
Incidence increases with age
< 30 y/o - < 2% incidence
>80 y/o - >75% incidence

8. Complications of Diverticular Disease
Infection
Generalized peritonitis
Diverticular abscess
Fistula
Bleeding

9. Diverticular Infection
Presentation: left lower quadrant pain, fever, localized tenderness, elevated wbc
Diagnosis – CT scan, U/S
Tx – tailored to Sx severity
Mild –outpt tx. Clear liquid diet, po Abx
Severe – inpt tx. Bowel rest, IVF, IV Abx
Recurrence – 30% after 1st episode, >50% after 2nd. Resection recommended after 2nd episode
Resection margin – to noninflammed bowel

10. Generalized Peritonitis
Results from perforation with widespread fecal contamination
Presentation – diffuse severe abdominal pain and peritonitis
Tx – Emergent laparotomy and Hartmann’s procedure is performed most commonly. Reconstruction of GI continuity 2 months later

11. Diverticular Abscess Dx – CT scan
Tx – Percutaneous drainage under CT guidance
Surgery – if percutaneous drainage is satisfactory, can wait for infection to clear and perform a one-stage resection (instead of a 2 stage i.e. Hartmann’s)

12. Diverticular Fistula Colovesicular – most common in men
Pneumaturia or fecaluria
UTIs
CT scan – shows air in the bladder
Colovaginal – most common in women
Colocutaneous
Enterocolic
Tx – Several weeks of Abx, resection

13. Diverticular Bleeding
From penetrating artery in dome of diverticulum
BRBPR
Not associated with previous melena
Resection of affected bowel

14. Polyps and Carcinoma Polyp Types Tubular - Pedunculated
Tubulovillous - Pedunculated
Villous - Sessile
Hamartoma
Inflammatory - IBD
Hyperplastic
May be premalignant

17. Polyps Presentation Treatment Usually asymptomatic May bleed
Detected during routine colonoscopy
Treatment
Pedunculated – snared and removed endoscopically
Villous – may be removed endoscopically if small
Villous – if >1.5 cm Bx, then do segmental resection

18. Colon Cancer Common presenting symptoms Weight loss Mass
Rectal bleeding
Virchow’s node
Blumer’s shelf
Anemia
Obstruction

21. Dukes Staging of Colon CA
STAGE
DESCRIPTION
5 YR SURVIVAL (%) A
Mucosa only
85-90 B1
Into, not through, Propria N(-)
70-75 B2
Through Propria N(-)
60-65 C1
B1 with N(+)
30-35 C2
B2 with N(+) 25 D
Distant mets
<5

22. Ulcerative Colitis
Mucosal inflammatory process of the colon with sx of bloody diarrhea and tenesmus
Initially – mucosal ulcers and crypt abscesses
Later – mucosal edema and pseudopolyps

24. Crohn’s Disease
Transmural inflammatory process most commonly of the distal ileum, can involve any area of the GI tract
Slight female predominance
Gross appearance of bowel: Creeping fat, wall thickening

25. Crohn’s Disease Common path changes fissures and fistulas
Transmural inflammation
Granulomas
Discontinuous distribution
Aphthoid ulcers

28. Colonic Obstruction Etiologies Most Common Adenocarcinoma (65%)
Diverticulitis (20%)
Volvulus (5%)
Other
Inflammatory disease
Benign tumors
Foreign bodies
Fecal impaction

32. Obstruction Presentation X-ray findings Distension
Cramping abdominal pain
N/V
Obstipation
X-ray findings
Distended colon
Air-fluid levels
No rectal air

33. Obstruction Physical Exam Distention Tympany
High pitched or tinkling bowel sounds
May feel mass

34. Obstruction Complete vs. incomplete bowel obstruction
Important b/c if complete – requires emergent operation
Cecal diameter of >10-12 cm needs some form of decompression
Partial obstruction – drip and suck

35. Obstruction
Treatment
IVF
NGT
Observation vs. definitive therapy

36. Obstruction Indications for emergent laparotomy
Cecal distention > 12 cm
Generalized sepsis
Acute abdomen – signs of perforation/peritonitis

37. Obstruction
Volvulus
Rotation of a segment of intestine on the mesentery
Sigmoid Colon – 70%
Cecum – 30%
Accounts for 5-10% of colonic obstruction
Second most common cause of complete obstruction
Ischemia leads to gangrene/infection/perforation

38. Obstruction Presentation of Volvulus Treatment of Volvulus
Similar to other obstruction causes
X-Rays – Classic coffee bean sign
Treatment of Volvulus
Sigmoidoscopy with rectal tube insertion to decompress sigmoid
Elective sigmoidectomy when pt is recovered
Emergent laparotomy if signs of bowel ischemia/perforation are present

39. Hemorrhoids
Definition: 3 vascular and connective tissue cushions in the anal canal, R anterolateral, R posteriolateral and L lateral
Internal hemorrhoids – above the dentate line
May bleed and prolapse, Do Not cause pain
External hemorrhoids – below the dentate line
May thrombose causing pain and itching

40. Hemorrhoid Grades First degree – bleed only
Second degree – bleed and prolapse but reduce spontaneously
Third degree – bleed, prolapse and require manual reduction
Fourth degree – bleed and are incarcerated

41. Hemorrhoid Treatment Medical for 1st and 2nd degree
Stool softeners, increased dietary fiber, etc
Surgical for refractory 3rd and 4th degree
I&D/Banding
Excisional hemorrhoidectomy
Complications:
10-50% incidence of urinary retention, bleeding, infection, sphincter injury and anal stenosis

42. Perianal Infections
Cryptoglandular abscess – in the intrasphincteric space. Dx – fluctuant mass. Tx – I&D
Necrotising anorectal infection (Fournier’s gangrene) – Dx – systemic signs of infection and perianal pain. Immediate wide surgical debridement. 50% mortality
Fistula in ano – Goodsall’s rule: posterior fistulas open to posterior midline, anterior fistulas penetrate in a radial direction toward the dentate line

43. Anal Malignancy
Squamous cell CA – wide local excision with chemo/rads tx if large
Epidermoid CAs – Nigro protocol (Chemo/rad), then surgical treatment reserved for local recurrence
AdenoCA – usually an extention of rectal CA, poor prognosis
Melanoma 1-3% of anal CA. Wide local excision. 5 yr survival <20%