A theory related to IBS deals with what’s called motility, meaning the coordinated motion of the intestines. After you eat, your intestines regularly contract and move food, or chyme, back and forth along their passageways, mixing it with digestive enzymes. The food then moves through the small intestine and into the large intestine. This can take between two and five hours.
When you haven’t eaten, your small intestines have a different pattern of movement that is nonetheless important. About every 90 minutes they contract, acting to sweep any remaining food particles toward the large intestine. Intestines move in waves.
Motility is connected to IBS in at least two ways. First, these movements can cause pain due to overactive nerves in the gut. Alternatively, lack of motility creates opportunity for bacteria overgrowth, and may lead to SIBO. Factors that can decrease motility include lack of sleep, lack of exercise, avoiding going to the bathroom and emotional distress.