Histopathological changes in the gastrointestinal tract due to medications: an update for the surgical pathologist (part II of II).

In keeping with the stated goal of providing the surgical pathologist with tools to recognize abnormalities of the gastrointestinal (GI) tract due to drugs (AGIDS), in part II of this review we embark in a more organ-based description of AGIDS. Adequate space is given to the numerous adverse gastrointestinal effects of nonsteroidal anti-inflammatory drugs. Pill esophagitis, esophagitis dissecans, proton pump inhibitors' effects, diaphragm disease, and the recently described effects of drugs such as olmesartan, mycophenolate, and of compounds such as yttrium-90 are highlighted among several others. The inclusion of drug effects in the differential diagnosis of "conventional" diseases (such as gastric antral vascular ectasia, graft-versus-host disease, ischemic colitis, acute colitis, collagenous enteritis, inflammatory bowel disease) is underscored to avoid sometimes significant diagnostic pitfalls. We reiterate the message of the necessary collaboration between pathologist and clinician in the recognition of these entities to provide the best patient care.