It's a myth that the definition of a normal bowel movement is having 1 movement each day because that is not true for everyone. There is no rule for frequency of bowel movements, but the general range is from 3 times a day to 3 times a week.
We investigate the dependence of the stickiness parameters $t_{ij}=1/(12\tau _{ij})$ -- where the $\tau_{ij}$ are the conventional Baxter parameters -- on the solute diameters $\sigma_{i}$ and $\sigma_{j}$ in multicomponent sticky hard sphere (SHS) models for fluid mixtures of mesoscopic neutral particles.
This accounts for the tendency of liquids to form spheres, the shape with the least amount of surface area. When these liquid spheres are distorted by gravity, they form the classic raindrop shape. Adhesion is when forces of attraction exist between different types of particles.