Rectal Disorders

Question 1

What is the dentate line?

Answer 1

a ring of folds 2 cm from the anal verge where the anal canal meets the rectum - it delineates where nerve fibers end (above the line, the area is insensitive to pain, below, the anal canal and anus are extremely sensitive)

Question 2

Where do veins from the rectum and anus drain?

Answer 2

portal vein (which leads to the liver and then the general circulation)

Question 3

Where do the lymph vessels of the anorectal area drain?

Answer 3

rectum -> lymph nodes in the lower abdomen; anus -> lymph nodes in the groin

Question 4

What are the segments of the lower digestive tract (in order starting from the anus)?

Answer 4

anus, rectum, sigmoid colon, descending colon, transverse colon, ascending colon, cecum, illeum, jejunum, duodenum

Question 5

What are hemorrhoids?

Answer 5

dilated, twisted (varicose - swelling and tortuous lengthening) veins located in the walls of the rectum and anus

Question 6

How are hemorrhoids classified?

Answer 6

internal (above the dentate line - venous return is portal) versus external (below dentate line - venous return is systemic)

Question 7

What type of bleeding can occur with hemorrhoids?

Answer 7

arterial - via the presinusoidal arterioles

Question 8

Where is the anorectal junction?

Answer 8

above the anal columns (which are above the dentate line)

Question 9

How are internal hemorrhoids classified?

Answer 9

By the degree to which they prolapse from the anal canal:
Grade I: do not prolapse below dentate line
Grade II: prolapse but reduce spontaneously
Grade III: prolapse and require manual reduction
Grade IV: are irreducible and may strangulate

Question 10

What are the major causes of hemorrhoids?

Answer 10

constipation (most common), prolonged straining, pregnancy, heredity, increased intra-abdominal pressure, aging

Question 11

What are the symptoms of hemorrhoids?

Answer 11

bleeding (bright red if internal or darker if external) on stool or in toilet, mucosal protrusion, discharge, soiled underwear, sensation of incomplete evacuation, pain (only if thrombosed - uncommon with internal but common with external)

Question 12

What is the treatment for hemorrhoids?

Answer 12

sitz baths, moist heat, suppositories, stool softeners, bed rest, stool bulking agents (psyllium/Metamucil or methylcellulose/Citrucel), surgery, banding

Question 13

What is an anal fissure?

Answer 13

longitudinal or elliptical tear in the anoderm distal to the dentate line

Question 14

What are the three types of anal fissures?

Answer 14

acute (appears like fresh laceration - erythematous), chronic (raised edges and fibrotic appearance - discoloration), underlying disease

Question 15

What are the causes of anal fissure?

Answer 15

primary (local trauma, passage of hard stool, high anal pressure) or secondary (inflammatory bowel disease, malignancy)

Question 16

What is elevated resting hypertonia of the internal anal sphincter?

Answer 16

higher max and mean resting anal pressures lead to higher levels of tonic contraction of the IAS (“tight ass” - high strung personality)

Question 17

What are the treatments for anal fissure?

Answer 17

four weeks of fiber, stool softeners, increased water intake, sitz baths, topical analgesic, topical vasodilator (0.2% nitroglycerin paste/nifedipine on peri-anal area 3-4 times per day)

Question 18

What are the cardinal features of hemorrhoids?

Answer 18

painless bleeding (bright red, coating stool), mild fecal incontinence, mucus discharge, anal pruritus, prolapse, pain (due to thrombosis)

Question 19

What are the differential diagnoses of hemorrhoids?

Answer 19

anal fissure, solitary rectal ulcer syndrome, polyps, rectal prolapse, colorectal/anal cancer, proctitis

Question 20

When should you refer for hemorrhoids?

Answer 20

melena, postural vital sign abnormalities, symptoms suggestive of malignancy, positive fecal occult blood, family Hx of cancer, change in bowel habits

Question 21

What is the most common location for an anal fissure?

Answer 21

posterior anal midline

Question 22

What are the presenting features of anal fissures?

Answer 22

tearing pain with passage of bowel movements, bright rectal bleeding, perianal pruritis, skin irritation

Question 23

What are the distinctions between acute and chronic anal fissures?

Answer 23

acute - appears like fresh laceration, superficial, heals in about 6 weeks; chronic - has raised edges, white/horizontally oriented fibers, accompanied by skin tags/papillae, may require surgical repair

Question 24

What are the differential diagnoses of anal fissures?

Answer 24

perianal ulcers (cause by IBD, granulomatous diseases, and STIs), anorectal fistula, solitary rectal ulcer syndrome

Question 25

What are some preventive measures for anal fissures?

Answer 25

proper anal hygiene, keeping anal area dry (towel or blow dry with hair dryer on low setting), wiping with soft cotton or moistened cloth, preventing constipation, avoiding straining, avoiding trauma, prompt treatment of diarrhea

Question 26

What would be the differential diagnosis of an anal fissure found other than at the posterior midline?

Answer 26

Crohn’s disease

Question 27

What are the recommended treatments for anal fissure patients who fail medical therapy?

Answer 27

botulism toxin A injection or lateral sphincterotomy