If the bread dissolves then so too must one's stomach lining and bowels, thus contributing to the floor being coated in either vomit or faeces.
The sandwich contents could be spilled onto the floor
They would be sick and/or lose control of their bladder/bowels
Other (please specify)
If the bread dissolves then so too must one's stomach lining and bowels, thus contributing to the floor being coated in either vomit or faeces.