Hello, For adults the best noninvasive test to diagnose intestinal bleeding is the color of the stools, Black tarry stools are diagnostic when not taking oral Iron tablets. And stools test for occult blood. For the latter need to be on a vegetarian diet for 3 days before the test is done, need to be repeated for 3 days. Indeed, there must be a good reason for getting Capsule endoscopy done like falling Hemoglobin, undiagnosed pain abdomen, frequent diarrhea, involuntary weight loss. It has immense value as a diagnostic tool provides a rapid diagnosis and treatment option at the same time. Magnesium citrate helps in cleaning up the intestines and helps the movement of the intestines to propel the camera, with no side effects. So it is used depends upon the clinical scenario. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Jaydeep Nanda