Final answer:
Foreign Body Sensation (FBS) occurs when intense visceral senses become part of our conscious awareness, as seen when swallowing a large bolus of food or feeling an overly full stomach.
Step-by-step explanation:
The cause of Foreign Body Sensation (FBS) involves visceral senses reaching conscious awareness. Visceral senses usually operate below the level of consciousness, but when they are intense enough, we can perceive them. The sensory homunculus, which is the map of the body in the primary somatosensory cortex, has only limited space for internal stimuli perception. For example, swallowing a large chunk of food may cause us to feel it as it moves through the esophagus, or a distended stomach after overeating can generate a noticeable sensation.