Clinical features vary according
The location of the obstruction.
The duration of obstruction.
The underlying pathology.
The presence or absence of
Cardinal features include:-
PAIN is the first symptom encountered, it occurs
suddenly and is usually severe..
It is colicky in nature and usually centred on the
umbilicus (small bowel) or lower abdomen (large
The pain coincides with the increasing peristaltic
With increasing distension, the colicky pain is replaced
by a mild & m0re constant diffuse pain.
The development of severe pain is suggestive of
strangulation, especially if that pain is continuous.
Colicky pain may not be a significant feature in post
operative simple mechanical obstruction and pain
does not occur in paralytic ileus..
More proximal the obstruction, more the frequency.
The more distal the obstruction, the longer the
interval between the onset of symptoms and
appearance of nausea & vomiting.
As obstruction progresses, the character of vomitus
alters from digested food to faeculent material, as a
result of the presence of enteric bacterial overgrowth..
Vomitus- food material, GI secretions..
Long standing low small bowel obstruction- feculent material.
In the small bowel, the degree of distension is
dependent on the site of obstruction & is greater the
more distal the lesion.
Central abdomen is usually distended in small bowel
obstruction; peripheral in small bowel obstruction..
Distension is a late feature of colonic obstruction.
May be ABSOLUTE(neither faeces nor flatus is passed)
or RELATIVE(only flatus is passed)
Absolute constipation(obstipation)is a cardinal feature
of complete intestinal obstruction. Exceptions:-
Mesenteric valvular obstruction
Functional obstruction associated with pelvic abscess
All cases of partial obstruction(in which diarrhoea may occur)
Visible peristalsis may be present which may be
provoked by gently flicking the abdominal wall.
Few images of
visible peristalsis in
Most common in small bowel obstruction because of
repeated vomiting and fluid sequestration resulting in
dry skin and tongue,
poor venous filling and
sunken eyes with oliguria
Blood urea level & haematocrit rise , giving a
Not a common feature
An increase in serum potassium, amylase or lactate
dehydrogenase may be associated with the presence
Pyrexia is rare & may indicate:
The onset of ischaemia
Inflammation or abscess associated with the obstructing
Hypothermia indicates septicaemic shock or neglected
case of long duration..
Localised tenderness indicates impending or
The development of peritonitis indicates impending or
overt infarction &/or perforation.
In case of large bowel obstruction, it is important to
elicit these findings in the right iliac fossa as the
caecum is most vulnerable to ischaemia
High pitched bowel sounds are present in majority of
patients with intestinal obstruction.
Bowel sounds may be scanty or absent if the
obstruction is long standing and the small bowel has
In early stage ‘visible peristalsis is the only sign.
Abdominal distension is the late sign.
Hernial orfices, surgical scars must be inspected.
During colic there may be muscle guarding. Slight tenderness
may be present between attacks of pain.
Tenderness and rigidity at the sight of obstruction usually
Only reveals resonant note of gaseous distension of bowel.
Presence of loud borborygmi, coinciding with intestinal colic
is very diagnostic.
Presence of mass on rectal examination within
or outside the lumen will give a clue to
diagnosis. Presence or absence of feces in
rectum should be noted. Absence means
obstruction is higher up. If present it should
be studied for presence of occult blood, which
include mucosal lesion e.g. cancer,
intussusception or infarction. Sigmoidoscopy
should be done if colonic obstruction is
Severe vomiting Moderate vomiting Late vomiting
Less distension Central distension Early distension ,
Colicky pain Central abdominal pain Less pain
Constipation late Varies in appearance Constipation is early
Severe dehydration Moderate Less dehydration
Comparison of clinical aspects
Strangulating Intestinal Obstruction is a SURGICAL
EMERGENCY. The features are:-
Constant pain , severe pain.
Generalised tenderness with rigidity & peritonism
Shock , especially if resistant simple fluid resuscitation.
When strangulation occurs in an external hernia, the
lump is tense, tender and irreducible and there is no
expansile cough impulse. There is erythema or
purplish discolouration of the above skin with
Classical presentation is with episodes of screaming
and drawing up of the legs in a previously well male
During attacks the child appears pale ; between
episodes he may be listless.
Vomiting may or may not occur at the outset but
becomes conspicuous and bile stained with time.
Initially passage of stool may be normal, whereas,
later, blood and mucous are evacuated- the ‘redcurrant
Classically abdomen is not usually distended.
A lump that hardens on palpation may be discerned
but this is present in only 60% of cases.
There may be associated feeling of emptiness in the
right iliac fossa (the sign of Dance).
On rectal examination, blood stained mucus may be
found on the finger.
Occasionally in extensive ileocolic or colocolic
intussusception, the apex may be palpable or even
protrude from the anus.
If unrelieved, progressive dehydration and abdominal
distension from small bowel obstruction will occur,
followed by peritonitis secondary to gangrene.
More common in females in fourth and fifth decades and
usually presents acutely with the classic feature of obstruction.
Ischemia is common.
At first the obstruction may be partial, with the passage of
flatus and faeces.
In 25% of cases examination may reveal a palpable tympanic
swelling in the midline or left side of abdomen.
The volvulus typically results in the caecum lying in the left
lying in the left upper quadrant.
Symptoms resembles that of large bowel obstruction.
Abdominal distension is an early and progressive sign, which
may be associated with hiccough and retching.
Constipation is absolute.
In some patient, the grossly distended torted left colon is
visible through the abdominal wall.