“She was a dream doctor for me,” Larry told me. “She knows that more information is going to make her a better surgeon, with a better outcome for the patient.”

Larry told Ramamoorthy that he felt like he was going to explode. His belly was severely distended. The rectal bleeding had worsened, and the volume of his stool was still in decline. Then came the PowerPoint. Among the data Larry presented were details about his C-reactive-protein levels, which measure inflammation, and which had multiplied nearly sixfold in the previous month. Last, he invited Ramamoorthy across campus to his Calit2 building, where he brought her into the Cave.

Like everyone who sees the virtual-reality room, Ramamoorthy was at first amazed. Then she was struck by how useful the images were. Inside our bellies, the intestines are a jumble of coiled tissue, resting among other organs and vital blood vessels. The twists and turns are not the same in everyone, so when a surgeon peers in, she encounters a layout that can differ from one person to the next and that, considering the coils are folded into such a small space, can be hard to sort out. In the operating room, the patient is placed on a reclining board with his head down, so that gravity eases compaction and makes the work a little easier. The first step in the procedure, under normal circumstances, is to insert a scope into the belly for a look around.

“We see kind of the lay of the land, and get a sense of what we have to do,” Ramamoorthy explained. She performs surgery with a state-of-the-art robot called the da Vinci Xi, a four-armed device that nearly fills the operating room. At the end of each arm is a narrow tube that can be inserted into the patient’s body; each insertion point is called a port. A small camera or the robot’s delicate fingers can be threaded through the tubes at these ports. Placement of the ports is crucial, because the camera and fingers that extend from them into the patient’s viscera must be set precisely in the area where Ramamoorthy intends to cut.

When using the da Vinci, Ramamoorthy does not peer directly into the patient’s body, but instead views it through a scope at the da Vinci’s workstation, which has a screen to project what the robot’s cameras see, and hand controls with which she can manipulate the robot’s fingers. The first step in Larry’s procedure would be to determine exactly where to place the ports in his belly.

Inside Transparent Larry, however, Ramamoorthy got a jump on the surgery a week early. She could see which portion of the colon would have to be removed, where it was located, and how it was shaped. All the peculiar twists and folds of Larry’s organs were displayed. She could see, near the upper-left end of his colon, where it was attached to his spleen, and where, in another spot, one of its folds pressed against his bladder—both areas of surgical risk. “You’re the doctor, not me,” Larry told her, pointing to a precise spot, “but I would start cutting here.” Pointing to another spot, he added, “And cutting here makes a good deal of sense.”