Kody (just turned 4) has had this same problem. I was absolutely terrified. Kody's started last September during the hurricane when our power was out for 9 days, and I had to change him from his normal food (raw, which was not available with the power outage). Us walking around with flashlights, and being in not too good moods, I am sure stressed him out, too.
I took him to the vet, who very calmly told me stress, or the change in food was probably what was causing the problem. He said to put him on metronidazole and a small dose of prednisone for 10 days. He thought this would take care of the problem.
I was very worried, as we had just gotten Kody 5 months before, and when I started researching about bengals, I came across several sites that talked about Irritable Bowel Disease. As he could see I was so upset, he said he could also do an endoscope to make sure there was not a further problem. They kept Kody overnight, gave him two enemas(don't even want to know how they accomplished that), and did the "colonoscopy." The vet said there was a little irritation which they did a biopsy of & thank God, it was nothing.
The metronidazole and prednisone did take care of the bleeding, but then a month or so later the same thing happened. He took both the medicines again.
Anyway to make a long story a little shorter--my vet has said that Kody just has a very , very sensitive stomach. He has taken one more round of the metronidazole (but no prednisone) and has been fine since. HIs usual diet consists of mainly raw and alittle bit of Taste of the Wild (a grain-free kibble). I used to give him just a little bit--probably about 1 1/2 ounces-- of different canned or pouched food, so if I was unable to get the raw for some reason I had an alternative. But after several incidences of a drops of blood the next day, I have cut out any canned or pouches. I'm sure it was just certain ingredients in certain ones, but it is easier to just cut them out. In an emergency Kody can just eat the Taste of the Wild.
I won't say I did not get a sick feeling every time I saw any blood. I read about a young bengal that died from the bleeding from IBD. And of course, MissMyra needs to get her kitty to the vet, but I have found in my "research" that the blood can be a common reaction to a food change and/or stress. Before the endoscope my vet also mentioned that cats can develop hemmoroids that get irritated and flare up at times.
I usually don't take exception at someone's posts (sorry, Linda), but the comment about someone taking themselves to the emergency room is ridiculous. I know people with hemmoroids(sp?) that have fresh blood on many occassions and don't rush to the doctor, much less the emergency room.
Please let us know what the vet does say.