Presentation is usually characterized by persistent abdominal cramps, episodic nausea, and vomiting, and abdominal distension.
MBO complicates 3-5% of all advanced cancers, with ovarian and colon cancers the mst implicated.
Usually presents periodically and resolves with passage of gas or stool.
Episodes of obstruction increase in frequency and last longer until near or complete obstruction occurs.
Presentation is gradual and management is usually not emergent.
Nasogastric tube suction is used to decompress the proximal bowel and intravenous fluids are provided to manage dehydration.
Abdominal x-rays are usually diagnostic.
Location of the obstruction is determined by presenting symptoms, radiographic characterization, and abdominal CT scans.
Abdominal CT scans have a sensitivity of 93%, specificity of 100% and accuracy of 94% in determining causes of bowel obstruction.
Rates of diagnostic accuracy much higher for abdominal CT than for ultrasound and plain x-ray films.
In a study of utilization of CT scan, the level of obstruction and its etiology were determined in 93% and 87% of cases, respectively.
Because carcinomatosis may be missed on abdominal CT scan ovarian and colon cancers have poor diagnostic efficacy of less than 20% for tumor deposits <0.5 cm, or for tumors located in the pelvis, mesentery or on the small intestine.
MRI of the abdomen has diagnostic sensitivity of 93% and specificity of 63% and accuracy of 81% in locating the site of tumor obstruction.