In horses, impactions commonly occur at which two regions of the gastrointestinal tract?

In horses, impactions commonly occur at which two regions of the gastrointestinal tract?

• A. Pelvic flexure and transverse colon
• B. Cecum and duodenum
• C. Jejunum and ileum
• D. Rectum and sigmoid

Answer: (A)

Impediments in horses tend to form where the large intestine slows and the lumen narrows, so ingesta can desiccate and pack into a firm mass. The pelvic flexure is a sharp bend in the large colon near the pelvic inlet; as content moves through this turn, motility can slow and water is reabsorbed, promoting drying and accumulation of ingesta. The transverse colon is another region where flow can slow and the lumen is relatively narrow, so contents can pile up there as well. Because these two sites regularly create conditions that favor impaction—slower transit and increased water loss—they are the most common locations for impactions in horses.

Impediments in horses tend to form where the large intestine slows and the lumen narrows, so ingesta can desiccate and pack into a firm mass. The pelvic flexure is a sharp bend in the large colon near the pelvic inlet; as content moves through this turn, motility can slow and water is reabsorbed, promoting drying and accumulation of ingesta. The transverse colon is another region where flow can slow and the lumen is relatively narrow, so contents can pile up there as well. Because these two sites regularly create conditions that favor impaction—slower transit and increased water loss—they are the most common locations for impactions in horses.