What is the appropriate investigation for a 65-year-old male patient with a history of right hemicolectomy (surgical removal of the right side of the colon) for cecal (part of the large intestine) cancer, presenting with abdominal pain, vomiting, and abdominal distension one year post-operatively?

From the Guidelines

The most appropriate investigation for this patient is option C, Colonoscopy, as it allows for direct visualization of the colon to identify potential obstructing lesions, anastomotic strictures, or recurrent cancer. This patient's presentation suggests a possible bowel obstruction, which is a common complication following colorectal cancer surgery, as noted in studies such as 1 and 1. Given his history of colon cancer, there is concern for recurrence or anastomotic stricture at the surgical site.

Key Considerations

• The patient's symptoms of abdominal pain, vomiting, and abdominal distension are consistent with a bowel obstruction, as described in 1.
• Colonoscopy can also be therapeutic in some cases by allowing for decompression or stent placement if an obstruction is found.
• Contrast studies like small bowel series or barium enema are less appropriate as initial investigations because they may not provide adequate visualization of the anastomotic site and could potentially worsen an obstruction, as suggested by 1.
• Laparotomy is too invasive as an initial diagnostic approach and should be reserved for cases where less invasive investigations have confirmed a surgical problem or when the patient's condition deteriorates.

Diagnostic Approach

• The patient's history and physical examination should guide the diagnostic approach, with consideration of laboratory tests to evaluate electrolyte imbalances and dehydration, as mentioned in 1.
• Imaging studies, such as abdominal CT scans, may be helpful in identifying the cause of obstruction, but colonoscopy is the most direct and informative initial investigation for this patient, given his history and symptoms.

From the Research

Appropriate Investigation for Small Bowel Obstruction

The patient's symptoms of abdominal pain, vomiting, and a distended but soft abdomen suggest a possible small bowel obstruction. The appropriate investigation for this condition is:

• Computed Tomography (CT) scan, as it is a powerful tool for assessing patients with small bowel obstruction 2, 3, 4
• CT can provide important information about the cause and site of obstruction, as well as the presence of a closed-loop obstruction or ischemia 2
• CT is considered the preeminent imaging modality for evaluating patients with suspected high-grade small-bowel obstruction 5

Alternative Investigations

Other investigations that may be considered, but are less appropriate as the initial investigation, are:

• Small bowel series, which can be used to diagnose small bowel obstruction, but is less sensitive than CT 6
• Barium enema, which plays a less significant role in the diagnosis of acute small-bowel obstruction 5
• Colonoscopy, which is not typically used to diagnose small bowel obstruction
• Laparotomy, which is a surgical procedure and not an investigation, but may be necessary if the patient requires surgical management for small bowel obstruction 2, 3, 4