Figure 2. Three endoscopic photographs of gastrointestinal cytomegalovirus disease causing mucosal ulceration. Left. Esophageal ulcer in a 25-year-old AIDS patient. Center. Ulcer in the gastric cardia seen by retroflexing the endoscope back toward the gastroesophageal junction. The patient was a 57-year-old man receiving corticosteroid therapy for severe chronic obstructive lung disease. Right. A yellow-based, irregular, colonic ulcer in a 54-year-old renal transplant patient.