This document discusses various causes and radiological findings of large bowel obstruction. The most common causes are cancer (60%), diverticulitis (20%), and volvulus (5%). Radiological findings of large bowel obstruction include a peripherally located distended bowel with haustral markings and no air distal to the site of obstruction. Barium enema can demonstrate the level and degree of obstruction, and may show findings like an "inverted U-shaped" sigmoid loop or "bird's beak" sign in sigmoid volvulus. CT scan with oral and IV contrast is also useful to evaluate bowel obstruction and its underlying cause.

2.  Cancer (60%)
 Diverticulitis( 20 % )
 Volvulus (5%)
 Adhesions
 Hernia
 Fecal impaction
 Foreign body

3.  F. Body
 Bezoars
 Gall stone
 Food Particles
 A. lumbricoides

4.  Neoplasms
 Lipoma
 Polyps
 Hematoma
 Lymphoma
 Carcinoid
 Secondary Tumors
 TB Strictures

5.  Postoperative adhesions.
 Congenital adhesions
 Hernia
 Volvulus

6. 1. Carcinoma:
The commonest cause that present with
obstruction.
2. Benign stricture:
Due to Diverticular disease, Ischemia,
Inflammatory bowel disease.
3. Volvulus:
Results from long redundant, faecaly loaded
colon with a narrow pedicle.
4. Hernia.

7. According to Leplac’s law: maximum pressure
is at the it’s maximum diameter, Cecum is at
the greatest risk of perforation .

8.  Abdominal pain
 Distention
 Constipation
 Nausea
 Vomiting

9.  Proximal obstruction: early bilious vomiting.
 Distal obstruction:
constipation, distension, vomiting feculent
material (bacterial overgrowth of contents).
 Distal obstruction: Less acute onset. Less
prominent .

10.  Past Medical Hx: remember to ask about
cardiac history (think about intestinal
ischemia), IBD, gallstones, cancer
 Meds: narcotics,antipsychotics
(ileus), diuretics (hypoK / ileus)
 recent weight loss (CA).

11. Normal Scout :
 Always request:
Supine, Erect and CXR
 Gas pattern:
Gastric,Colonic and 1-2
small bowel
 Fluid Levels:
 Free gas under diaphragm
 Look for calcification
 Look for soft tissue
masses.

12.  look for free air under diaphragm, dilated
bowel loops, air-fluid levels.
 Note: if cecal diameter >12cm, there is a risk
of perforation.
 Barium enema
 Bowel follow-through
 CT scan- with PO/IV contrast

13. Large bowel
 Peripheral
 Max.diameter 8 cm .
 Presence of
haustration
 Colon is filled with
feces which has
bubbly appearance
 Air fluid levels are
few and large.
Small Bowel
 Central
 Max. diameter 5 cm.
 Vulvulae coniventae
 Air fluid levels are
many and small .

16. What are the radiological findings of large
bowel obstruction?
 Obstructed colon usually appears as a
peripherally located distended bowel with
haustral markings.
 No air distal to site of obstruction.
 Sometimes the mass may be seen.

17. How is bowel obstruction different from
paralytic ileus?
 There will be paucity of gas in bowel beyond
the site of obstruction, unlike in paralytic
ileus where gas can be seen in the rectum.

19. Barium enema radiograph
showing dilated colon. No
transition zone is visible

20. contrast (trip
Used with iv , oral and rectal contrast (triple contrast).
◦ The level and degree of obstruction .
◦ The cause: volvulus, hernia, luminal and mural causes
◦ The degree of ischaemia
◦ Free fluid and gas
◦ Able to demonstrate abnormality in the bowel wall, mesentery,
mesenteric vessels and peritoneum.
Ensure: patient vitally stable with no renal failure and no previous
allergy to iodine iodine

21.  Diagnostic points :
◦ Abdominal plain films
 Inverted U-shaped appearance of distended sigmoid loop
 Loss of haustra
 Coffee-bean sign à midline crease corresponding to
mesenteric root in a greatly distended sigmoid
 Sigmoid volvulus – bowel loop points to RUQ
 Cecal volvulus – bowel loop points to LUQ
 Bird’s-beak or bird-of-prey sign à seen on barium enema in
sigmoid volvulus as it encounters the volvulated loop
 Apple core appearance : ca colon.

25. Ba contrast enema.contrast-
filled rectum illustrates the
"bird's beak" sign (white
arrow), corresponding to the
luminal narrowing at the site
of sigmoid obstruction. This
is the characteristic
presentation of a sigmoid
volvulus

26.  20 year old woman presented to the ED with
12 hours of abdominal pain, nausea. and
vomiting low grade fever.
 No past surgical history
 PMH: Polycystic ovarian disease

27. Dilated cecum

28. Cecum

29. Contrast
In Descending colon
Cecum

30. Barium Enema
Point of Obstruction
Ascending colon

31. Cecal volvulus

33. Coiled spring appearance with barium
enema.
Intussception

35. u/s abdomen
showing multiple
concentric rings of
increased and
decreased
echogenicity
Intussception

38. Barium enema: displacement
of the sigmoid colon by a
pelvic mass from
endometrial carcinoma

40. Barium radiograph demonstrates a
typical "apple-core" lesion (arrows)
caused by adenocarcinoma of the
small bowel, producing a partial
obstruction with dilated proximal
bowel.