Swallowable camera pill robots now can anchor to your intestines safely.
"The anchoring robot would be swallowed like a normal pill and move through the body until it reached the gut. Then a doctor, using a wireless control, would tell the robot when to expand its legs and anchor. It would be good not only for snapping images, but also potentially for biopsies, drug delivery, heat treatment, and other treatment applications."
And more here with the swallowable sensor SmartPill.
"The SmartPill is an ingested, wireless device for measuring the health of the digestive system. As it passes through the digestive tract, the capsule transmits data to a receiver, which is later returned to the doctor and the information downloaded onto a laptop computer. (Courtesy of SmartPill Corp.)"