Rapid Intestinal Transit

Alternative names: Bowel transit time, Small bowel transit time, Colonic transit time, Gastrointestinal motility

Intestinal transit time refers to how long it takes for food to move from the stomach to the anus after it has been broken down in the stomach.  Rapid Intestinal Transit results in inadequate nutrient absorption.

The time taken for food to pass through the gastrointestinal tract depends on various factors.  It normally takes around 2½ to 3 hours for 50% of stomach contents to empty into the intestines, and 4 to 5 hours for the stomach to empty completely.  A 50% emptying of the small intestine then takes another 2½ to 3 hours, and the final stage – transit through the colon – normally takes 16-40 hours.  High-fiber diets generally result in lower transit times.

Causes and Development

The human intestinal tract, comprising the small intestine (center), large intestine (surrounding), and colon (bottom)

Aside from those mentioned below, there are many other things that decrease the amount of time that stool stays in the intestines, including:

• surgical bypass of part of the intestine
• prostaglandins
• serotonin
• acidic foods
• stress and anxiety are also common causes
• Zollinger-Ellison syndrome (over-production of acid due to a tumor).

Signs and Symptoms

There is no "normal" color of stool because it varies from person to person and depends on what was consumed and the digestive process.  As food moves through the digestive tract, it usually turns from green to yellow-orange to brown.  Bile and bacteria are what gives stool its final brown color.

Rapid intestinal transit is often suspected when stool color is greenish, meaning that the final stages of digestion have not had time to take place.