What is the specific function attributed to the insoluble fiber component in lima beans regarding bowel movements?

Adding bulk to stool and promoting regularity

Lima beans uniquely provide both soluble and insoluble types of dietary fiber, each contributing differently to overall digestive wellness. The insoluble fiber operates mechanistically much like a natural cleansing agent within the gastrointestinal tract. Its primary role is to absorb water and, crucially, to add substantial physical bulk and mass to the resulting stool material. This increase in volume is necessary to stimulate the intestinal musculature effectively, which is the key mechanism for promoting consistent peristalsis and ensuring regularity. By performing this function, insoluble fiber is instrumental in the prevention of constipation and the maintenance of predictable, consistent bowel movements, establishing a foundational aspect of gut health.