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.

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.

The treatment of large bowel obstruction depends on the underlying cause and severity. Initial management often involves stabilizing the patient, which may include intravenous fluids, electrolyte correction, and nasogastric tube insertion to relieve pressure. Surgical intervention is frequently required, especially in cases of complete obstruction or when the cause is a tumor or severe stricture. In some instances, endoscopic procedures may be used to relieve the obstruction.

The prognosis for patients with large bowel obstruction varies based on the cause and timeliness of treatment. Early intervention generally leads to better outcomes. However, complications such as bowel perforation or infection can occur if the obstruction is not addressed promptly. Chronic obstructions or those caused by malignancies may have a more guarded prognosis.

Large bowel obstructions can arise from several causes. Common etiologies include colorectal cancer, diverticular disease, volvulus (twisting of the intestine), and strictures from inflammatory bowel disease. Less frequently, impacted feces or foreign bodies can lead to obstruction. Identifying the underlying cause is crucial for effective treatment.

Large bowel obstruction is more common in older adults, particularly those over the age of 65. The incidence is higher in individuals with a history of colorectal cancer or diverticular disease. While it can occur in both men and women, certain causes, like volvulus, may have a gender predilection.

The pathophysiology of large bowel obstruction involves the interruption of normal intestinal transit. This can lead to increased pressure within the bowel, reduced blood flow, and potential bowel wall damage. If left untreated, it can result in bowel perforation, peritonitis (inflammation of the abdominal lining), and sepsis, a life-threatening infection.

Preventing large bowel obstruction involves addressing risk factors and underlying conditions. Regular screening for colorectal cancer, managing diverticular disease, and maintaining a healthy diet to prevent constipation are important preventive measures. Early detection and treatment of potential causes can also reduce the risk of obstruction.

Large bowel obstruction is a serious condition that requires prompt diagnosis and treatment. It presents with symptoms like abdominal pain and distension and can result from various causes, including tumors and strictures. Treatment often involves surgical intervention, and the prognosis depends on the cause and timeliness of care. Understanding the risk factors and maintaining regular health screenings can aid in prevention.

If you suspect a large bowel obstruction, it is important to seek medical attention promptly. Symptoms such as severe abdominal pain, bloating, and constipation should not be ignored. Diagnosis typically involves imaging tests, and treatment may require surgery. Early intervention can improve outcomes, so understanding the signs and risk factors is crucial for maintaining digestive health.

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