[header] How to treat diarrhea in hamsters [title] Stop feeding your hamster fresh vegetables. [step] In small quantities, fresh vegetables are part of a healthy, balanced. They are very nutritious and have extra moisture that keeps hamsters well hydrated. 
Eating too many vegetables, though, can cause diarrhea because of too much moisture. To help stop your hamster's diarrhea, take fresh vegetables out of its diet.