Which statement about intestinal obstruction is true?

• A. It can be simple (mechanical) or functional (paralytic ileus)
• B. It is always caused by infection
• C. It never causes vomiting
• D. It is solely due to cancer

Answer: (D)

Intestinal obstruction fits into two broad categories: a simple mechanical blockage and a functional loss of propulsion known as paralytic ileus. In a mechanical obstruction, a physical barrier such as adhesions, a hernia, a tumor, or a stricture blocks the lumen so contents can’t pass. In paralytic ileus, the bowel doesn’t move properly due to disrupted nerves or muscles after surgery, illness, electrolyte problems, or peritoneal irritation, leading to distension without a discrete blocked segment. Because of this dual nature, infection isn’t the defining cause, and cancer isn’t the sole cause—cancer can contribute by mass effect, but many other mechanical and functional factors can produce obstruction. Vomiting, abdominal distension, and altered bowel sounds are common features as the obstruction develops. So the true statement is that obstruction can be either mechanical or functional, rather than caused solely by one factor like cancer.