I reported about Israel’s Check-cap previously (Feb 2012) that requires no prior preparation or hospital visit.  After 4 years, trials on 54 participants of its ingestible and disposable low-dose 3D imaging capsule proved safe and well tolerated and detected small and large polyps.

http://ir.check-cap.com/2016-05-25-Check-Cap-Announces-Preliminary-Data-Evaluating-its-Preparation-Free-Colon-Screening-Capsule