What Does Bright Red Patch On Stomach Indicate?

Husband just developed bright red patch on stomach area. He just started lisinopril 10mg. 2 days ago. He is type 2 diabectic, had cath heart stent put in 2 wks ago, he has high blood pressure, he is on plavix, prilosec and other bp meds. He had low hgb, (7.2) hospitalized had 2 pts blood. His kidneys got worst after the dye. Should we call his doctor. We just noticed this today.Also he was on lasic, then hospital said stop, but now Kidney doctor said go back on lasic, and he prescribed the lisinopril 10mg. Please advise.