Internal hernias occur through defects of the mesentery or into

the retroperitoneal space and are not visible.

An impulse can often be felt in a hernia during coughing

(cough impulse). Identify a hernia from its anatomical site and

6.14 Causes of ascites

Diagnosis Comment

Common

Hepatic cirrhosis with portal

hypertension

Transudate

Intra-abdominal malignancy with

peritoneal spread

Exudate, cytology may be

positive

Uncommon

Hepatic vein occlusion (Budd–Chiari

syndrome)

Transudate in acute phase

Constrictive pericarditis and right

heart failure

Check jugular venous pressure

and listen for pericardial rub

Hypoproteinaemia (nephrotic

syndrome, protein-losing

enteropathy)

Transudate

Tuberculous peritonitis Low glucose content

Pancreatitis, pancreatic duct

disruption

Very high amylase content

Anterior

superior

iliac spine

Inguinal

ligament

Internal

inguinal ring

External

inguinal ring

Spermatic

cord

Femoral

artery

Femoral

vein

Pubic

tubercle

Femoral canal

Fig. 6.19 Anatomy of the inguinal canal and femoral sheath.

The physical examination • 111

6

on coughing or on conscious contraction by the patient. Beyond

the anal canal, the rectum passes upwards and backwards along

the curve of the sacrum.

Spasm of the external anal sphincter is common in anxious

patients. When associated with local pain, it is probably due to

an anal fissure (a mucosal tear). If you suspect an anal fissure,

give the patient a local anaesthetic suppository 10 minutes

before the examination to reduce the pain and spasm, and to

aid examination.

Examination sequence

• Explain what you are going to do and why it is necessary,

and ask for permission to proceed. Tell the patient that the

examination may be uncomfortable but should not be

painful.

• Offer a chaperone; record a refusal. Make a note of the

name of the chaperone.

• Position the patient in the left lateral position with their

buttocks at the edge of the couch, their knees drawn

up to their chest and their heels clear of the perineum

(Fig. 6.22).

• Put on gloves and examine the perianal skin, using an

effective light source.

• Look for skin lesions, external haemorrhoids, fissures and

fistulae.

• Lubricate your index finger with water-based gel.

• Place the pulp of your forefinger on the anal margin and

apply steady pressure on the sphincter to push your

finger gently through the anal canal into the rectum

(Fig. 6.23).

• If anal spasm occurs, ask the patient to breathe in

deeply and relax. If necessary, use a local anaesthetic

suppository or gel before trying again. If pain persists,

examination under general anaesthesia may be

necessary.

• Ask the patient to squeeze your finger with their

anal muscles and note any weakness of sphincter

contraction.

Fig. 6.20 Right inguinal hernia.

Obstructed

proximal bowel

Collapsed

distal bowel

Covering of

hernia sac Contents of sac (small bowel in

this example)

Neck of hernia

Fig. 6.21 Hernia: anatomical structure.

hernia contains bowel, obstruction may occur. If the blood supply

to the contents of the hernia (bowel or omentum) is restricted,

the hernia is strangulated. It is tense, tender and has no cough

impulse, there may be bowel obstruction and, later, signs of

sepsis and shock. A strangulated hernia is a surgical emergency

and, if left untreated, will lead to bowel infarction and peritonitis.

Rectal examination

Digital examination of the rectum is important (Box 6.15). Do

not avoid it because you or the patient finds it disagreeable. The

patient’s verbal consent is needed, however, and the examination

should be carried out in the presence of a chaperone.

The normal rectum is usually empty and smooth-walled, with

the coccyx and sacrum lying posteriorly. In the male, anterior

to the rectum from below upwards, lie the membranous urethra,

the prostate and the base of the bladder. The normal prostate

is smooth and firm, with lateral lobes and a median groove

between them. In the female, the vagina and cervix lie anteriorly.

The upper end of the anal canal is marked by the puborectalis

muscle, which is readily palpable and contracts as a reflex action

6.15 Indications for rectal examination

Alimentary

• Suspected appendicitis, pelvic abscess, peritonitis, lower

abdominal pain

• Diarrhoea, constipation, tenesmus or anorectal pain

• Rectal bleeding or iron deficiency anaemia

• Unexplained weight loss

• Bimanual examination of lower abdominal mass for diagnosis or

staging

• Malignancies of unknown origin

Genitourinary

• Assessment of prostate in prostatism or suspected prostatic cancer

• Dysuria, frequency, haematuria, epididymo-orchitis

• Replacement for vaginal examination when this would be

inappropriate

Miscellaneous

• Unexplained bone pain, backache or lumbosacral nerve root pain

• Pyrexia of unknown origin

• Abdominal, pelvic or spinal trauma

112 • The gastrointestinal system

Fig. 6.22 The correct position of the patient before a rectal

examination.

Fig. 6.23 Rectal examination. The correct method for inserting your

index finger in rectal examination.

   

Fig. 6.24 Examination of the rectum. A and B Insert your finger, then rotate your hand. C The most prominent feature in the female is the cervix.

D The most prominent feature in the male is the prostate.

6.16 Causes of abnormal stool appearance

Stool appearance Cause

Abnormally pale Biliary obstruction

Pale and greasy Steatorrhoea

Black and tarry (melaena) Bleeding from the upper

gastrointestinal tract

Grey/black Oral iron or bismuth therapy

Silvery Steatorrhoea plus upper gastrointestinal

bleeding, e.g. pancreatic cancer

Fresh blood in or on stool Large bowel, rectal or anal bleeding

Stool mixed with pus Infective colitis or inflammatory bowel

disease

Rice-water stool (watery

with mucus and cell debris)

Cholera

• Palpate systematically around the entire rectum; note any

abnormality and examine any mass (Fig. 6.24). Record the

percentage of the rectal circumference involved by disease

and its distance from the anus.

• Identify the uterine cervix in women and the prostate in

men; assess the size, shape and consistency of the

prostate and note any tenderness.

• If the rectum contains faeces and you are in doubt about

palpable masses, repeat the examination after the patient

has defecated.

• Slowly withdraw your finger. Examine it for stool colour

and the presence of blood or mucus (Box 6.16).

Haemorrhoids (‘piles’, congested venous plexuses around the

anal canal) are usually palpable if thrombosed. In patients with

chronic constipation the rectum is often loaded with faeces.

Faecal masses are frequently palpable, should be movable and

can be indented. In women a retroverted uterus and the normal

cervix are often palpable through the anterior rectal wall and a

vaginal tampon may be confusing. Cancer of the lower rectum

is palpable as a mucosal irregularity. Obstructing cancer of the

upper rectum may produce ballooning of the empty rectal cavity

below. Metastases or colonic tumours within the pelvis may

be mistaken for faeces and vice versa. Lateralised tenderness

suggests pelvic peritonitis. Gynaecological malignancy may cause

a ‘frozen pelvis’ with a hard, rigid feel to the pelvic organs due

to extensive peritoneal disease, such as post-radiotherapy or

in metastatic cervical or ovarian cancer.

Benign prostatic hyperplasia often produces palpable

symmetrical enlargement, but not if the hyperplasia is confined

Investigations • 113

6

• Remove the obturator and carefully examine the anal canal