http://www.medirabbit.com/EN/GI_diseases/Mechanical_diseases/bloat.htm
True bloat is a distressful and dangerous condition in rabbits. It should not be confused with stasis or ileus a condition that takes a few days to develop and is characterized by reduced motility of the intestine, or the presence of some gas in the digestive system caused by food. Bloat is a dreaded condition in rabbits, with poor prognosis, causing excruciating pain. Most rabbit savvy vets often opt to humanely put the rabbit to sleep, to spare it more suffering.
Bloat is caused by an abnormal accumulation of gas that leads to an extreme distension of the stomach. The stomach feels hard and the rabbit looks like a balloon. The rabbit shows signs of terrible pain and may have difficulties to breath properly. When bloat reaches a certain point in rabbits, it becomes irreversible. This is due to the facts that the stomach wall of rabbits is not as elastic as in many other animals. The distended stomach (its volume can double) will, furthermore, compress the main blood vessels that lead blood to and from the heart, causing secondary cardiovascular collapse and heart failure. Blood electrolyte imbalance lead to convulsions. At this stage, the condition is fatal.
Causes of bloat remain unknown. It may related to overeating, exercising immediately after eating are suspected in most animals, lack of fiber in the diet, change of diet, excessive drinking or stress, or result from a pyloric blockage, gastric ulcers or other digestive problems.
