Gallstone ileus obstruction most commonly occurs at which part of the small intestine?

Gallstone ileus obstruction most commonly occurs at which part of the small intestine?

• A. Stomach
• B. Ileum
• C. Jejunum
• D. Duodenum

Answer: (B)

When a gallstone creates a fistula between the gallbladder and the bowel, it can travel through the GI tract and become lodged where the lumen is narrowest, causing a mechanical obstruction. The ileum, especially near the ileocecal valve, is the most common site because it has the smallest, least distensible lumen among the small-bowel segments. This bottleneck, combined with relatively slower distal peristalsis, makes it the typical destination for a wandering gallstone. The stomach, duodenum, and proximal portions of the small intestine have larger diameters and are less prone to impaction by a stone, though a very large stone can rarely cause obstruction higher up (with duodenal involvement known as Bouveret syndrome). So, the distal ileum near the ileocecal valve is the classic site of gallstone ileus obstruction.

When a gallstone creates a fistula between the gallbladder and the bowel, it can travel through the GI tract and become lodged where the lumen is narrowest, causing a mechanical obstruction. The ileum, especially near the ileocecal valve, is the most common site because it has the smallest, least distensible lumen among the small-bowel segments. This bottleneck, combined with relatively slower distal peristalsis, makes it the typical destination for a wandering gallstone. The stomach, duodenum, and proximal portions of the small intestine have larger diameters and are less prone to impaction by a stone, though a very large stone can rarely cause obstruction higher up (with duodenal involvement known as Bouveret syndrome). So, the distal ileum near the ileocecal valve is the classic site of gallstone ileus obstruction.