Blood in Stool...?

Fiance saw blood in his stool this evening... Last time he saw such he had been newly diagnosed with UC; that was over 10+ years ago. He told me not to worry, or to go to jump online but I cannot help it. I see the worry in his face and he was very short, almost angry with me this evening. There has been no new issues, no changes to diet or meds. He has been very, very stressed this month! He did however have a colonoscopy and some endoscopic band ligations last week. I do all the research, checking in with the doctors for booking/follow up, etc.. What should I be looking for in this area? I will be asking him daily if more blood is appearing, is there any specific questions I should be asking? Has anyone had such an issue? Thank you in advance for any advice/direction. -A