Download Chapter 20 Anus, Rectum, and Prostate Examination of the anus

Chapter 20
Anus, Rectum, and Prostate
Examination of the anus and rectum is performed:
As part of an annual well-person examination for both men and women
And, in men, includes examination of the prostate
When the patient has a specific concern or problem
Physical Examination Preview
Physical Examination Preview (Cont.)
Inspect the sacrococcygeal and perianal area for the following:
Skin characteristics
Lesions
Pilonidal dimpling and/or tufts of hair
Inflammation
Excoriation
Physical Exam Preview (Cont.)
Inspect the anus for the following:
Skin characteristics and tags
Lesions, fissures, hemorrhoids, or polyps
Fistulae
Prolapse
Physical Examination Preview (Cont.)
Insert finger and assess sphincter tone.
Palpate the muscular ring for the following:
Smoothness
Evenness of pressure against examining finger
Palpate the lateral, posterior, and anterior rectal walls for the following:
Nodules, masses, or polyps
Tenderness
Irregularities
Physical Examination Preview (Cont.)
In males, palpate the posterior surface of the prostate gland through the anterior rectal wall for
the following:
Size
Contour
Consistency
Mobility
Physical Examination Preview (Cont.)
In females, palpate the cervix and uterus through the anterior rectal wall for the following:
Size
Shape
Position
Smoothness
Mobility
Physical Examination Preview (Cont.)
Have the patient bear down and palpate deeper for the following:
Tenderness
Nodules
Withdraw the finger and examine fecal material for the following:
Color
Consistency
Blood or pus
Occult blood by chemical test if indicated
Anatomy and Physiology
Anal Canal and Rectum
Anal canal: 2.5 to 4 cm long
Opens onto the perineum
Visible tissue at the external margin of the anus is moist, hairless mucosa
Juncture with the perianal skin is characterized by increased pigmentation and, in the
adult, the presence of hair
Anal Canal and Rectum (Cont.)
Anal Canal and Rectum (Cont.)
Anal canal
Lower half of the canal is supplied with somatic sensory nerves.
Sensitive to pain
Upper half is under autonomic control.
Relatively insensitive to pain
Anal Canal and Rectum (Cont.)
Anal Canal and Rectum (Cont.)
Anal canal (Cont.)
Normally kept securely closed by concentric rings of sphincter muscles
Internal
Smooth muscle
Involuntary
External
Striated
Voluntary
Controls defecation
Anal Canal and Rectum (Cont.)
Anal canal (Cont.)
Lined by columns of mucosal tissue (columns of Morgagni)
Spaces between the columns are called crypts
Anal glands empty
Inflammation of the crypts can result in fistula or fissure formation
Anal Canal and Rectum (Cont.)
Anal canal (Cont.)
Anastomosing veins cross the columns
Zona hemorrhoidalis
Internal hemorrhoids
Lower segment of the anal canal contains a venous plexus that drains into the inferior
rectal veins
External hemorrhoids
Anal Canal and Rectum (Cont.)
Rectum: 12 cm long
Rectum lies superior to the anus.
Proximal end is continuous with the sigmoid colon.
Rectal ampulla stores flatus and feces.
Rectal wall contains three semilunar transverse folds (Houston valves).
Lowest of these folds can be palpated
Prostate
Prostate: 4 × 3 × 2 cm
Located at the base of the bladder and surrounds the urethra
Posterior surface accessible by digital examination
Anterior rectal wall
Prostate (Cont.)
Prostate
Three lobes
Median sulcus: left and right lateral lobes
Median lobe: not palpable
Contains active secretory alveoli that contribute to ejaculatory fluid
Infants and Children
First meconium stool is ordinarily passed within the first 24 to 48 hours after birth and indicates
anal patency.
Common for newborns to have a stool after each feeding (the gastrocolic reflex)
Control of external anal sphincter by 18 to 24 months
Myelination complete
Prostate undeveloped until puberty
Pregnant Women
Decreased GI tract tone and motility produce constipation
Dietary habits and hormonal changes
Pressure in the veins below the enlarged uterus increases
Development of hemorrhoids
Aggravated by labor
Protrusion and inflammation
Older Adults
Degeneration of afferent neurons in the rectal wall:
Interferes with the process of relaxation of the internal sphincter
Increased pressure sensation threshold in rectum
Stool retention
Loss of external sphincter tone
Fecal incontinence
Older Adults (Cont.)
Prostate
Fibromuscular structures of the prostate gland atrophy
Often obscured by benign hyperplasia of the glandular tissue
Loss of function of the secretory alveoli
Review of Related History
History of Present Illness
Changes in bowel function
Character: number, frequency, consistency of stools; presence of mucus or blood; color
Onset and duration
Accompanying symptoms
Medications: iron, laxatives, stool softeners
History of Present Illness (Cont.)
Anal discomfort: itching, pain, stinging, burning
Relation to body position and defecation
Straining at stool
Blood and mucus
Interference with activities of daily living and sleep
Medications: hemorrhoid preparations
History of Present Illness (Cont.)
Rectal bleeding
Color: bright or dark red, black
Relation to defecation
Amount
Changes in stool
Associated symptoms
Medications: iron, fiber additives
History of Present Illness (Cont.)
Males: Changes in urinary function
History of enlarged prostate or prostatitis
Symptoms: hesitancy, urgency, nocturia, dysuria, change in force or caliber of stream,
dribbling, urethral discharge
Medications: antihistamines, anticholinergics, tricyclic antidepressants, 5-alphareductase-inhibitors
Past Medical History
Hemorrhoids
Spinal cord injury
Males: prostatic hypertrophy or cancer
Females: episiotomy or fourth-degree laceration during delivery
Colorectal cancer or related cancers: breast, ovarian, endometrial
Family History
Rectal polyps
Colon cancer or familial cancer syndromes
Prostatic cancer
Personal and Social History
Travel history: areas with high incidence of parasitic infestation, including zones in the United
States
Diet: inclusion of fiber and amount of animal fat
Colorectal or prostate cancer risk factors
Use of alcohol
Infants and Children
Stool characteristics
Bowel movements accompanied by crying, straining, bleeding
Feeding habits
Bowel control and potty training
Associated symptoms
Congenital anomaly
Pregnant Women
Gestation and estimated delivery date
Exercise
Fluid intake and diet
Use of complementary or alternative therapies
Medications: prenatal vitamins, iron
Older Adults
Change in bowel habits or character
Associated symptoms
Dietary changes
Males: enlarged prostate and urinary symptoms
Examination and Findings
Equipment
Gloves
Lubricant
Penlight
Drapes
Test for occult blood
Positioning
Rectal examination can be performed with the patient in any of these positions:
Knee-chest
Left lateral with hips and knees flexed
Standing with the hips flexed and the upper body supported by the examining table
Sacrococcygeal and Perianal Areas
Inspect for:
Lumps
Rashes
Inflammation
Excoriation
Scars
Pilonidal dimpling
Tufts of hair at the pilonidal area
Sacrococcygeal and Perianal Areas (Cont.)
Palpate for:
Tenderness
Inflammation
Signs of:
Perianal abscess
Anorectal fistula or fissure
Pilonidal cyst
Pruritus ani
Anus
Inspect for:
Skin lesions
Skin tags or warts
External hemorrhoids
Fissures
Fistulae
Clock referents are used to describe the location of anal and rectal findings.
12 o’clock is in the ventral midline and 6 o’clock is in the dorsal midline.
Sphincter
External sphincter tone
Lax sphincter may indicate neurologic deficit.
Extremely tight sphincter can result from scarring, spasticity caused by a fissure or other
lesion, inflammation, or anxiety about the examination.
Sphincter (Cont.)
Rectal pain is almost always indicative of a local disease.
Irritation, rock-hard constipation, rectal fissures, or thrombosed hemorrhoids
Anal Ring
Tone and texture
Smooth and exerts even pressure
Nodes or irregularities
Rectal Walls
Lateral and posterior
Nodules, masses, irregularities, polyps, or tenderness
Internal hemorrhoids not ordinarily felt unless they are thrombosed
Anterior
Contact with the peritoneum
Peritoneal inflammation
Nodularity of peritoneal metastases
Shelf lesions
Posterior surface of prostate
Prostate
Via anterior rectal wall
Size
Contour
Median sulcus
Lateral lobes
Consistency
Mobility
Tenderness
Uterus and Cervix
Retroflexed or retroverted uterus is usually palpable through rectal examination.
Cervix may be palpable through the anterior rectal wall.
Stool
Characteristics
Color
Blood
Pus
Mucus
Infants and Children
Inspect anus, perineum, and buttocks
Redness or irritation
Masses
Discharge or bleeding
Perirectal protrusion
Rectal abscesses
Texture and tone
Anal contraction
Infants and Children (Cont.)
Examine newborn for patency of anus.
Lightly touch the anal opening, which should produce anal contraction (“anal wink”).
Lack of contraction may indicate a lower spinal cord lesion.
Routinely inspect the anal region and perineum:
Redness, masses, or swelling
Infants and Children (Cont.)
Rectal examination is not routine for infants and children; do rectal examination for:
Pain
Bleeding
Rectal protrusion or abscesses
Stool abnormalities
Rectal examination is routine for adolescents.
Pregnant Women
Inspect and palpate for expected changes.
Stool changes
Iron preparations
Hemorrhoids
Size
Extent
Location (internal or external)
Discomfort to the patient
Signs of infection or bleeding
Older Adults
Inspect and palpate for:
Decreased sphincter tone
Stool character
Enlarged prostate
Polyps
Abnormalities
Anus, Rectum, and Surrounding Skin
Pilonidal cyst
Loose hairs penetrate the skin in the sacrococcygeal area.
Anal warts (condyloma acuminata)
Result of infection with the human papillomavirus
Anus, Rectum, and Surrounding Skin (Cont.)
Anal cancer
Most are squamous cell carcinomas, which are associated with HPV infection
Adenocarcinomas originate in the glands near the anus
Basal cell carcinoma and malignant melanoma
Anorectal fissure
Tear in the anal mucosa
Anus, Rectum, and Surrounding Skin (Cont.)
Perianal or perirectal abscesses
Infection of the soft tissues surrounding the anal canal or mucus secreting anal glands
Abscess formation occurs in the deeper tissues
Usually polymicrobial
Anaerobes
Anus, Rectum, and Surrounding Skin (Cont.)
Anal fistula
Inflammatory tract that runs from the anus or rectum and opens onto the surface of the
perianal skin or other tissue
Caused by drainage of a perianal or perirectal abscess
Pruritus ani
Commonly caused by fungal infection in adults and by parasites in children
Anus, Rectum, and Surrounding Skin (Cont.)
Hemorrhoids
External hemorrhoids: varicose veins that originate below the anorectal line and are
covered by anal skin
Internal hemorrhoids: varicose veins that originate above the anorectal junction and are
covered by rectal mucosa
Anus, Rectum, and Surrounding Skin (Cont.)
Polyps
Occur anywhere in the intestinal tract
May be malignant or benign
Anus, Rectum, and Surrounding Skin (Cont.)
Rectal cancer
Adenocarcinomas comprise the large majority of rectal cancers
Rectal prolapse
Protrusion or the rectal mucosa, with or without the muscular wall, through the anal ring
Prostate
Prostatitis
Inflammation of the prostate gland
Prostate (Cont.)
Benign prostatic hypertrophy (BPH)
Continuing enlargement of the prostate gland
Common in men older than 50 years
Prostatic cancer
99% of prostate cancers are adenocarcinomas
Develops from the gland cells within the prostate
Children
Enterobiasis (roundworm, pinworm)
Adult nematode (parasite) lives in the rectum or colon and emerges onto perianal skin to
lay eggs while the child sleeps.
Imperforate anus
Rectum may end blindly, be stenosed, or have a fistulous connection to the perineum,
urinary tract, or, in females, the vagina.
Question 1
The internal anal canal is lined with mucosal tissue that fuse to form the anorectal junction. This is
called:
A. Columns of Morgani
B. Houston valves
C. Gastrocolic reflex
D. Zona hemorrhoidalis
Question 2
In males, which surface of the prostate gland is accessible by digital examination?
A. Median lobe
B. Posterior
C. Superior
D. Anterior
Question 3
In the infant, the internal and external anal sphincters are under involuntary control because:
A. The prostate is small and inactive
B. Myelination of the spinal cord is incomplete
C. Degeneration of the afferent nerves
D. Encopresis
Question 4
An expected anal or rectal finding late in pregnancy is the presence of:
A. Rectal prolapse
B. Skin tags
C. Polyps
D. Hemorrhoids
Question 5
During the digital rectal examination have the patient bear down to:
A. Spread the buttocks
B. Examine the prolapse of hemorrhoids
C. Relax the internal sphincter
D. Relax the external sphincter