Yellowish Stool 4 days After Hospital Stay for Intestinal Bleeding

I have a question about gastrointestinal bleeding and recovery expectations. One week ago on a Friday, I began having dark red bloody stools. Forty hours later I entered the hospital with dizziness, extreme fatigue, paleness and shortness of breath. Over the next 48 hours I received 2 units of blood, saline, an upper endoscopy and a colonoscopy, leaving the hospital on a Tuesday.

Before my first transfusion, my HmG (hemoglobin) was 8.9, then dropped to 7.0 after saline drip, 8.4 following a transfusion and colonoscopy, then slowly rising to 10.8 upon receiving another transfusion (ref range of 11.5-16.5).

My HCT (hematocrit) was low at 17.5, slowly rising to 29 upon leaving hospital (ref range of 35-55). Today, four days after 2nd transfusion, my HmG is still 10.8 and HCT is up to 31.5. For reference, four weeks ago, HmG was 14.6 and HCT was 42.5.

I am taking iron and taking it easy though still driving and walking. Today, I feel very lightheaded again, but have had no bleeding since Monday morning just before the colonscopy. But my stool has been a mild yellowish paleish color (grey poupon mustard color, a little less yellow) and all diarrhea since Monday evening.

So is it:
- normal to still be lightheaded (though less than before)
- have no improvement in HmG in 3 days
- still have diarrhea
- with an abnormal stool color?

By way of background, I am 45, 6'1", 255 lbs, have a slightly fatty liver and recurring upper right quadrant pain or discomfort, history of kidney stones, and frequent intestinal discomfort. The colonoscopy found diverticulosis and two polyps in the rectum. The doctor said the bleeding must have come from one of two diverticula in the descending colon however the bleeding had recently stopped so the actual source was never seen. There was left over debris in the colon, so I have to go back for a screening colonoscopy. I've read the darker the blood, the higher up in digestive track is the source. This wasn't black but a very dark reddish brown with some maroon/dark purplish at the fringes.

So my other question is whether the blood source might be from somewhere other than the left colon, also in light of some continuing symptoms (though less dizziness, no blood and less fatigue) e.g. gall bladder, liver, pancreas, small intestine, part of colon not clearly visible, etc? The endoscopy was clean. ALT and AST are within range, 58/10-60 and 32/10-42 respectively. These are typical scores for me over last three years, though I was slightly elevated 10 months ago at 68 and 43. I also have high cholesterol but stopped Lipitor due to these elevations and some joint pain.

Thanks!