Which diagnostic imaging process allows for direct visualization of intestine?

CT/capsule endoscopy. Ct or ct enterography will allow you the best global picture of everything in the abdomen. Ultrasound can show solid abdominal organs but is limited evaluating air containing structures like large/small bowel. For direct visualization of the mucosa, capsule endoscopy (small cameral you swallow) may work. It all depends on the clinical indication.