A large bowel obstruction (LBO) can involve a blockage of the whole or part of the colonic lumen. Firstly, if the obstruction is complete, the patient presents with acute and profound symptomatology; in a partial large bowel obstruction the symptoms are milder and it is not a threatening condition.

A patient affected by partial large bowel obstruction presents with a medical history of constipation, but and reports the passing of a reduced amount of gas as well as stool. In a complete large bowel obstruction, the main symptoms are usually characteristic, with the individuals complaining of abdominal pain and distention, complete inability to pass fecal matter and gas, and vomiting [1] [2] [3]. Patients who report with severe abdominal pain, rigidity, guarding, fever and signs of shock, with a medical history of constipation and distention should be treated immediately, as a large bowel obstruction can likely evolve into a perforation and subsequent peritonitis.

Other findings that may also be noticed are usually not caused by LBO itself, but by the underlying pathology. Intermittent left-lower-quadrant pain in the abdomen over a long period of time and generally recurring constipation may be caused by diverticulitis. This sign together with colorectal cancer and volvulus forms the three primary causes of LBO [4]. Weight loss may be reported by individuals who are affected by colorectal cancer.

• Soft Tissue Mass

  Abdominal computed tomography revealed hugely dilated large bowel up to the sigmoid colon, with sigmoid soft tissue mass. [ncbi.nlm.nih.gov]

  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. 11.  look for free air under diaphragm, dilated [slideshare.net]

• Pediatric Disease

  disease; however, it is estimated that 5-16% of all intussusceptions in the Western world occur in adults. [emedicine.medscape.com]

• Sulfur Granules

  A diverting loop colostomy was performed, and pathology revealed sulfur granules from the extracted IUD that grew Actinomyces. [ncbi.nlm.nih.gov]

• Paraumbilical Hernia

  Computed tomography of the abdomen revealed a paraumbilical hernia containing a segment of transverse colon resulting in partial bowel obstruction. [acgcasereports.gi.org]

• Hyperresonance

  The bowel sounds may be normal early on but usually become quiet, and the abdomen is hyperresonant to percussion. Palpation of the abdomen may reveal tenderness. [emedicine.medscape.com]

• Constipation

  A 76-year-old man presented to the emergency department with diffuse abdominal pain and constipation. In the few months before this admission the patient had complained of strenuous micturition. [ncbi.nlm.nih.gov]

  He has a history of diverticulosis and chronic constipation. He last had a bowel movement 1 week ago and has not had any flatus in the past day. He reports 2 episodes of vomiting at home. [step2.medbullets.com]

• Vomiting

  A 32-year-old female patient presented to the emergency department with complaints of diffuse abdominal pain and constipation for 10 days with progressive abdominal distention and vomiting. [ncbi.nlm.nih.gov]

  He reports 2 episodes of vomiting at home. On physical exam, his abdomen is distended and there is diffuse tenderness to palpation. A CT of his abdomen and pelvis shows dilated loops of bowel and a suspicious mass at the transition point. [step2.medbullets.com]

   Abdominal pain  Distention  Constipation  Nausea  Vomiting 8.  Proximal obstruction: early bilious vomiting.  Distal obstruction: constipation, distension, vomiting feculent material (bacterial overgrowth of contents).  Distal obstruction: [slideshare.net]

• Abdominal Pain

  Abnormalities of the left hemidiaphragmatic contour on plain radiographs of the chest should suggest the diagnosis in patients who have abdominal pain, colonic dilatation, and a history of abdominal injury. [ncbi.nlm.nih.gov]

• Nausea

  The diagnosis of adult obstruction was made from a history of constipation, abdominal distension, abdominal pain, nausea, and radiographic features of large bowel obstruction. Laparotomy was performed on all patients after resuscitation. [ncbi.nlm.nih.gov]

  The most common symptoms include not being able to pass gas or have a bowel movement, nausea, vomiting, bloating, abdominal swelling and pain. There are different treatments depending on the type of bowel obstruction you have. [my.clevelandclinic.org]

  Causes include Carcinoma (60%) Diverticulitis (20%) Volvulus Strictures, such as from Crohn disease Fecal impaction Hernia Imperforate anus or meconium ileus in pediatric population Increases in prevalence with age Clinical Findings Abdominal distension Nausea [learningradiology.com]

  Secondary Objectives: are to evaluate the symptom response (including abdominal pain, distention, bowel frequency and consistency, and nausea and emesis) and complication rate of treatment of malignant large bowel obstruction with endoscopic stent placement [clinicaltrials.gov]

• Abdominal Distension

  Snap Shot A 65 yo presents with abdominal distension and colicky pain. Introduction Adhesions are the most common cause of all bowel obstructions. [medbullets.com]

  The diagnosis of adult obstruction was made from a history of constipation, abdominal distension, abdominal pain, nausea, and radiographic features of large bowel obstruction. Laparotomy was performed on all patients after resuscitation. [ncbi.nlm.nih.gov]

  […] obstruction of the colon Causes include Carcinoma (60%) Diverticulitis (20%) Volvulus Strictures, such as from Crohn disease Fecal impaction Hernia Imperforate anus or meconium ileus in pediatric population Increases in prevalence with age Clinical Findings Abdominal [learningradiology.com]

  A 64-year-old man presented with abdominal distension, pain, and vomiting for 5 days. Computed tomography scan of the abdomen showed dilated small intestine and colon, air in the biliary tree, and a calcified mass in the sigmoid colon. [amjmed.org]

  […] pain more constant, vomitting later, much more distension •Presentation: Colicky abdominal pain,constipation/obstipation –Vomiting - late( faeculent) abdominal distension –Fever, sepsis and shock, peritonism •Leftsided tumours: Change in bowel habit, [cram.com]

The diagnosis of large bowel obstruction is made primarily via the use of imaging modalities, as well as laboratory tests that do not exactly serve the diagnostic purposes but help to comprehensively evaluate the patient's status. The elimination of ileus as a possible alternative diagnosis is also carried out via laboratory tests.

Blood tests involve:

• Complete blood count. A significantly raised white blood count indicates peritonitis, as opposed to uncomplicated large bowel obstruction.
• Biochemical profile, including electrolytes, lactate dehydrogenase (LDH), glucose, alkaline phosphatase (ALP), urea, creatinine, cholesterol, triglycerides, c-reactive protein (CRP), erythrocyte sedimentation rate (ESR) etc. Prothrombin type (PT-INR) and serum lactate should also be measured, with the latter helping in the detection of potential perforation. Liver function tests are also recommended.
• Stool guaiac test
• Crossmatch

Imaging modalities include the following:

• Radiography: It constitutes the very initial imaging method used, with a specificity and sensitivity of approximately 70 and 80% [5]. Abdominal radiographs are obtained in a supine and erect position and can illustrate air-fluid levels and colonic diameter; free air indicative of pneumoperitoneum due to perforation is also depicted.
• Computerized Tomography scan (CT scan): It can provide the physician more information than a plain radiograph; this accounts for the rising replacement of X-rays by a CT scan in the present day [6]. The administration of contrast media can differentiate between partial and complete obstruction, small and large bowel obstruction and ileus [6].
• Multiple detector computed tomography (MDCT). Its sensitivity is 96%, while the specificity is approximately 93% [7] [8]. The cause of LBO, potential complications, and its ability to differentiate between pseudo-obstruction, volvulus of the colon and other pathologies render it an extremely useful means of evaluating a possible large bowel obstruction.

• Bowel Distention

  During the freeze cycle of endoscopic spray cryotherapy, high-flow nitrogen was injected onto the tumor, which caused bowel distention. [acgcasereports.gi.org]

  Bowel distention leads to third-space volume loss, resulting in dehydration and electrolyte abnormalities. Symptoms are less severe in partial bowel obstruction. Diagnosis is confirmed on imaging with contrast-enhanced CT scan and abdominal x-rays. [amboss.com]

  Pathophysiologic effects of bowel distention on intestinal blood flow. Am J Surg. 1969;117(2):228–34. PubMed Google Scholar 9. Stillwell GK. The law of Laplace. Some clinical applications. Mayo Clinic Proc. 1973;48(12):863–9. Google Scholar 10. [link.springer.com]

  The key radiographic findings of LBO are the presence of large-bowel distention, dilated loops greater than 9 cm in diameter in the cecum, and dilated loops greater than 6 cm in diameter in the remainder of the colon [1]. [ajronline.org]

• X-Ray Abnormal

  Home » Tutorials » Abdominal X-ray Tutorials » Abdominal X-ray - Abnormal bowel gas pattern » Introduction » 1 2 3 4 5 6 » Conclusion Key points Dilatation of the caecum 9cm is abnormal Dilatation of any other part of the colon 6cm is abnormal Abdominal [radiologymasterclass.co.uk]

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3. Pujahari AK. Decision Making in Bowel Obstruction: A Review. J Clin Diagn Res. 2016 Nov;10(11).
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5. Gore RM, Levine MS. Textbook of Gastrointestinal Radiology. 3rd ed. Philadelphia, PA: Saunders, Elsevier; 2008.
6. Jaffe T, Thompson WM. Large-bowel obstruction in the adult: classic radiographic and CT findings, etiology, and mimics. Radiology. 2015 Jun;275(3):651-63.
7. Frager D, Rovno HD, Baer JW, Bashist B, Friedman M. Prospective evaluation of colonic obstruction with computed tomography. Abdom Imaging. 1998;23:141–6.
8. Godfrey EM, Addley HC, Shaw AS. The use of computed tomography in the detection and characterisation of large bowel obstruction. N Z Med J. 2009;122:57–73.