Colon Dimensions

Question 1

Anus

Answer 1

0-4 cm

Question 2

Rectum

Answer 2

4-16cm

~ 12cm long

Question 3

Rectosigmoid

Answer 3

15-17cm

Question 4

Sigmoid

Answer 4

17-57cm

~ 40cm long

Question 5

Descending colon

Answer 5

57-82 cm

~ 25cm long

Question 6

Transverse colon

Answer 6

82-132cm

~ 50cm long

Question 7

Ascending colon

Answer 7

132-147cm

~15 cm long

Question 8

Cecum

Answer 8

@150th cm

Question 9

Summary all parts of colon

Answer 9

0-4: anus (4cm)
4-16: Rectum (12cm)
15-17cm: rectosigmoid
17-57cm: sigmoid (40cm)
57-82cm: descending colon (25cm)
82-132cm: transverse colon (50cm)
132-147cm: ascending colon (15cm)
150cm: cecum

Question 10

DRE and anoscopy

Answer 10

8cm

Identifies 10% of colorectal cancer

Question 11

Rigid proctoscopy

Answer 11

Detects 20-25% of CRC

25cm

Question 12

Flexibile sigmoidoscopy

Answer 12

60cm
(Sigmoid: 17-57cm)
Adv: reaches proximal left colon, or even splenic flexure
Dis: gives inaccurate measurements if used at rectum

Question 13

Colonoscopy

Answer 13

100-160cm
Up to terminal ileium
Able to take biopsies

Question 14

CEA

Answer 14

Cut-off: 2.5-5.0 ng/mL

Question 15

Hemorrhoids

Answer 15

Left lateral (3 o’clock)
Right posterior (7 o’clock)
Right anterior (11 o’clock)