10.4: Intestinal Obstruction
- Page ID
- 14847
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)ACR – Gastrointestinal – Suspected Small Bowel Obstruction
Case 1
Adhesions
Clinical:
History – This patient has had numerous ventriculo-peritoneal shunts. He has had many abdominal surgeries for revisions of the shunt tubing. No other significant history.
Symptoms – Abdominal pain and bloating. Diminished appetite. No flatus or bowel movements for 24 hours. Vomiting watery green fluid for 12 hours.
Physical – The abdomen was distended and mildly, diffusely tender. The bowel sounds were infrequent and high-pitched. The abdomen was tympanitic. No rebound or guarding. Scars were seen from his previous surgeries.
DDx:
Suspected Small Bowel Obstruction
Imaging Recommendation
ACR–Gastrointestinal – Suspected Small Bowel Obstruction, Variant 1
Three views of the Abdomen
CT of the Abdomen
ODIN Link for Small Bowel Obstruction images (3 Views of the Abdomen), Figure 10.6A and B: mistr.usask.ca/odin/?caseID=20170410113920578
Imaging Assessment
Findings:
There was a paucity of bowel gas in the colon. The small bowel was dilated and there were multiple air-fluid levels (> 3 in number) in the small intestine. No calculi seen. The ventriculo-peritoneal shunt tubing was noted.
Interpretation:
Suspicious for high-grade, or complete, small bowel obstruction.
Diagnosis:
Adhesions, small bowel obstruction from restrictive band.
Discussion:
An abnormality in the small bowel lumen, the small bowel wall, or an abnormality extrinsic to the small bowel can cause a blockage of the lumen. This prevents antegrade passage of gas and fluid. Initially, the small bowel increases peristaltic effort to move the contents forward (hyperperistalsis, high-pitched bowel sounds), then later the peristalsis ceases.
The hyperperistalsis clears the bowel downstream of the obstruction resulting in a relatively clear distal bowel (sigmoid colon, rectum).
Causes of small bowel obstruction include:
- Adhesions after previous abdominal or pelvic surgery
- Inflammatory bowel disease
- Hernias
- Gallstones
- Malignancy
- Ingested foreign body
- Intussusception – more common in children
X-ray findings may include:
- Dilated bowel – small bowel > 2.5 – 3 cm, cecum > 10 cm, transverse colon > 6 cm, sigmoid colon > 4cm
- Gas and fluid in the bowel.
- Air-fluid levels in small bowel > 3 in number
- Less gas and fluid in the bowel downstream of obstruction.
Case 2
Ventral Abdominal Hernia
Clinical:
History – This patient had a previous laparotomy for a perforated diverticulum 10 years ago. A noticeable hernia was present in the ventral abdomen and it was noted to have enlarged over the last two years.
Symptoms – Abdominal pain and bloating. Diminished appetite. No flatus or bowel movements for 48 hours. Vomiting watery green fluid for 24 hours.
Physical – The abdomen was distended and mildly, diffusely tender. The bowel sounds were infrequent and high-pitched. The abdomen was tympanitic. A large, firm, mass was noted in the ventral abdominal wall. It was not particularly tender to palpation. No rebound or guarding.
DDx:
Suspected Small Bowel Obstruction
Ileus
Bowel Perforation
Imaging Recommendation
ACR–Gastrointestinal – Suspected Small Bowel Obstruction, Variant 1
Three views of the Abdomen
CT of the Abdomen
ODIN Link to Abdominal Wall Mass with Small Bowel Obstruction images (Ultrasound, 2 Views of the Abdomen, and CT), Figure 10.7A and B: mistr.usask.ca/odin/?caseID=20170410112613962
Imaging Assessment
Findings:
Ultrasound – A mixed echogenicity mass is seen in the lower mid abdomen. There is suspicion for a fat containing intestine within the hernia sac. No calculi seen.
CT – There was a soft tissue mass in the lower, ventral, abdominal wall, subcutaneous fat. This has the appearance of a hernia. There was intestine in the hernia sac. The visualized small intestine was dilated, consistent with a small bowel obstruction.
Interpretation:
Moderate grade small bowel obstruction.
Diagnosis:
The patient had a ventral, bowel containing hernia, with small bowel obstruction secondary to entrapment of the bowel in the hernia sac (incarceration).
Attributions
Figure 10.6A Abdominal x-ray, supine, suspicious for SBO by Dr. Brent Burbridge MD, FRCPC, University Medical Imaging Consultants, College of Medicine, University of Saskatchewan is used under a CC-BY-NC-SA 4.0 license.
Figure 10.6B Abdominal x-ray, decubitus, suspicious for SBO by Dr. Brent Burbridge MD, FRCPC, University Medical Imaging Consultants, College of Medicine, University of Saskatchewan is used under a CC-BY-NC-SA 4.0 license.
Figure 10.7A Ultrasound of Abdomen displaying a mass in the abdominal wall fat by Dr. Brent Burbridge MD, FRCPC, University Medical Imaging Consultants, College of Medicine, University of Saskatchewan is used under a CC-BY-NC-SA 4.0 license.
Figure 10.7B CT Scan of the Abdomen displaying a mass in the abdominal wall by Dr. Brent Burbridge MD, FRCPC, University Medical Imaging Consultants, College of Medicine, University of Saskatchewan is used under a CC-BY-NC-SA 4.0 license.