1. Image of the Day 10 : Acute Intestinal Obstruction, Small Bowel.
Muhamad Na’im B. Ab Razak (MD USM)
Disclaimer: The history was modified and no breach of patient’s confidentiality are made in
the publication of this case study.
A 70 years old gentleman with Benign Prostate Hypertrophy and history of laparotomy few
years back presented with abdominal pain, nausea and altered bowel habit for three days
duration. Patient was co-morbidly well but since for the past few days, he was having colicky
abdominal pain centering at periumbilical region and radiates to the whole abdomen. The pain
score was 5-6/10 and not relieve by medication taken at Klinik Kesihatan. He also complains
of passing out small, hard and black stool once daily since three days ago and not passing
flatus on the day of admission. His oral intake was also reduce in view of feeling nauseated
each time taking meal and only took clear fluids.
On examination, he look cachexic, afebrile, normal vital sign and pink conjunctiva. Per
abdomen examination, there is a lower midline incision scar and right transverse lower
incision scar. No discoloration of the abdomen noted. On palpation, the abdomen is soft and
slightly distended with voluntary guarding around the umbilical area. No mass palpable per
abdomen. Auscultation reveals hyperactive bowel sound and percussion note is resonance. Per
rectal examination reveals empty rectum and moderately enlarged prostate which is firm,
present of median sulcus and normal mucosa. Examination of other systems reveal no

2. abnormality. Bedside ultrasound shows dilated small bowel with fluid and faecal material
inside the bowel lumen. There is no free fluid collection and no abnormality of other organ
noted.
Labarotory investigation shows normal FBC, coagulation profile and no acidosis. The
pottasium however is borderline high but other electrolytes are normal.
The Abdominal X Rays shows dilated small bowel with intraluminal gas and minimal faecal
materials. There was no sign of extra luminal gas. A well defined rounded opacity also noted
inside the pelvic cavity, ? of bladder stone. A diagnosis of Acute Intestinal Obstruction of
the Small Bowel secondary to Adhesion Colic was made and managed conservatively with
1) 4 hourly vital sign monitoring, 2) Ryle’s tube insertion with free flow and 4 hourly
aspiration, 3) Keep nil by mouth, 4) CBD insertion, 5) Strict monitoring of Input/Output
charting, 6) Analgesia PRN with IV Fentanyl 50 mcg, 7) IVD fluids with 3 pints of NS and 2
pints of D5% over 24 hours, 8) DXT monitoring, 9) IV Omeprazole 40 mg OD, 10) KIV for
CVP insertion if patient become unwell 11) Replacement of loss fluid from RT, 12) Group
Screen and Hold (GSH) and 13) KIV for laparotomy if non resolving of obstruction or signs
of bowel perforation or gangrene present.

3. Discussion
Intestinal obstruction is a very common surgical emergency that pose a high morbidity and
mortality to the patient with inappropriate management. Being divided into large and small
bowel obstruction, both are caused by mechanical obstruction and non mechanical. 80% of
bowel obstructions involves the small bowel. The mechanical small bower obstruction is
further divided into the luminal cause (foreign body, impacted fecal material, gallstone,
bezoars, parasites and polypoidal tumors), intrinsic (atresia, tumors and inflammatory
structures like TB and Crohn disease) and and extrinsic cause (adhesion, hernias, volvulus,
intussuception, band, inflammation and neoplastic mass).
Other type of obstruction in small bowel is coined as ‘Paralytic Ileus’ and most commonly
occurs post operatively (up to 72 hours), pancreatitis and mesenteric infarct. Less common
cause would be Pseudo obstruction (Ogilvie’s syndrome), Opiates, anticholinergics,
retroperitoneal hemorrhage and metabolic cause (ketoacidosis, severe hypokalaemia).
Although this entry is to discuss about small bowel obstruction, it is vital to differentiate
between small vs large bowel obstruction as the definitive management is different. The table
illustrated below will give a summary for it. My Version is modified from original table by Dr
Chew Keng Sheng, Emergency Physician of University Science Malaysia. You can refer to
his original table via this link. http://emergencymedic.blogspot.cm/2010/11/bowel-
obstruction_15.html
Acute Intestinal Obstruction
Character Small bowel Large bowe
Pain Colicky periumbilical pain. Not predominant, if present
then located at lower
abdomen
Vomiting Early in proximal obstruction It is often a late sign due to
and late in distal obstruction the incompetency of the ileo-
caecal valve
Abdominal Distension Little or no in proximal Significant abdominal
obstruction and significant in distension.
distal obstruction
Bowel opening Late sign Altered bowel opening.
Absolute obstruction when
no bowel opening and not
passing flatus.

4. Radiologic features Small bowel features: large bowel features:
Valvulae conniventes – folds Haustrations: incomplete
that cross the lumen crossing of folds across the
completely lumen
Normal features of small
bowel:
- No more than 3 mm wall
thickness
- Generally no more than 3
air fluid levels
- No more than 3 cm
diameter
3,6,9 rule Maximal normal diameter in small bowel 3 cm
Maximal normal diameter in large bowel 6 cm
Maximal normal diameter in cecum 9 cm
Misscelenous Paralytic ileus usually In colorectal Carcinoma
painless.
Left sided tumors: generally
presented with altered bowel
habit, blood or mucus PR,
mass PR
Right sided tumors: generally
presented with weight loss,
anemia, less obstructive
symptoms
Other Physical sign to look - Dehydration
for - Hyper peristaltic bowel sound. Diminish in paralytic
ileus or perforation/ infarction.
- Hypovolumic shock in late stage
- Abdominal mass
- Hernia orifices
- Rectal examination – blood, palpable mass.
Specific type of mechanical - Strangulated
obstruction - Closed loop
- Volvulus
- Intussusception.
Warning sign - Constant severe pain of sudden onset is omnious sign
of bowel strangulation or infarct.
- Presence of shock, leukocytosis, peritoneal irritation
should rise of suspicion of strangulated obstruction.

5. Investigation that you should take includes 1) blood investigation (FBC, Coagulation profile,
BUSE/Creat, LFT if indicated, Ca2+, Mg2+ and Po4- if indicated, blood culture if patient is
septic), 2) Imaging (Plain radiograph, Ultrasound abdomen, water soluble contrast study if
needed.
As for management, the conservative management as i outlined in the case history is adequate
and almost 80% of the cases will resolve with conservative management. Indication for
surgical intervention includes 1) non resolving obstruction after 48 hours of conservative
management, 2) present of primary underlying cause like hernia, obstructing tumor, 3) sign of
peritoneal irritation.
Reference
Christian M & Gordon LC, “Acute Abdomen: Intestinal Obstruction”, Emergency Surgery,
Surgery 26:3, Elsevier Ltd 2008