I'd go for the pumpkin as well. It sounds like your poor little guy is suffering from some constipation. If it was bright red and very little blood then it's probably a small fissure (small tear) in his rear area from all the strain. I wouldn't be too worried about it unless it continues in larger amounts. Please keep us updated. I hope he feels better soon.     
				__________________  LeeAnn   Harley      Remember..  Dog is  God Spelled Backwards            |