if there is a full blockage and the gi tract has no 'activity' at all then surgery is the only option
a full blockage with ileus would be fatal, especially given the rapid onset of hepatic lipidosis in the anorexic rabbit
a partial obstruction/impaction can break down and pass with ongoing aggressive treatment- ie pain relief, fluid therapy, prokinetics (as long as there is not a
total obstruction) and an osmotic laxative
if the obstruction is at the pylorus, then death usually occurs as a result of cardiac arrest. The stomach rapidly dilates due to the formation of gas from the fermenting ingesta that cant pass out of the stomach due to the obstructed pylorus
the dilated stomach stops the lungs from being able to inflate leading to eventual cardiac arrest
even if the stomach is decompressed by 'tubing' the rabbit it will swell up again if the obstructed pylorus is not cleared.
http://wildpro.twycrosszoo.org/S/00dis/PhysicalTraumatic/AcuteGIT_ObstructionRabbits.htm
if a full obstruction is further down in the gi tract, in the intestines, it too would require prompt surgical intervention, decompression of the stomach may also be necessary in this situation too
a
fully obstructed rabbit would be unlikely to survive for more than 12 hours without surgery
a
partial obstruction could move through with aggressive treatment, but if prokinetics are used there is a risk of intestinal rupture if the obstruction were total