Results. The one that works the best with little or no side effects. One must be careful not to chronically use stimulant laxatives but intermittent use has role in some patients. Osmotic laxatives are usually the safest, but patient with underling kidney disease should always be careful and discuss with your doctor.
Ercp. Usually just some bloating. But this is a dangerous test. 10% get pancreatitis, and one in 500 die from it. Make sure there is a really good reason to do it.