Although diet is the most common cause of gastric stasis, any condition that changes GI tract motility can result in this disease. As the movement of material through the GI tract slows, the ingesta sits longer at any point, particularly the stomach and cecum and the body extracts more fluid than normal. This serves to dehydrate the ingesta, which causes further slowdown of GI motility in a vicious cycle. The result is dry impacted material in the stomach as well as the cecum, which ceases to move altogether. The rabbit then stops eating and drinking because nothing is moving and further aggravates the condition.
Rabbits always have some hair in their stomach contents.
They groom themselves constantly and swallow the hair. In the rabbit, hair is mixed with stomach contents in a loose mass. As the stomach contents dehydrate as described above, the largest particles are left behind which includes the hair. The liquid stomach contents gradually turn into a solid tightly adhered mass. If you look closely at a hairball you can see that it is made up of both hair and dried stomach contents.