>>508149118 (OP)When a person of size defecates, they will inevitably have difficulty wiping the feces from their buttocks. The large rolls of fat obstruct the hand from entering areas where cleaning is necessary, and the arm is often obstructed from the full range of motion required. The feces also have a tendency to get stuck in mats of anal public hairs, which are common in people of size due to the inability to groom that area.
When walking or sitting, such as at a supermarket, the heat generated within the highly compressed areas of adipose tissue causes intense sweating within the intergluteal cleft. The "shart" appearance is then caused by the motion of walking or adjusting in one' seat due to anal itching from unwiped fecal matter. These actions pump the liquidized fecal matter up and out of the posterior, similar to how soap spreads when one rubs their palms together during hand washing.
Passing gas will further increase the stain in the clothing, as the flatulence will be propelled through a tiny tunnel of air between the adipose tissue and exit the flesh as a highly compressed blast of methane, propelling the accompanying fecal matter at a high velocity similar to a sneeze. This is not a "shart" within itself, but can have a very similar effect as one.
