Well given that most of us have intestinal issues...
https://www.kickas.org/ubbthreads/ubbthreads.php?ubb=showflat&Number=434620&page=1https://www.kickas.org/ubbthreads/ubbthre...6009#Post396009sadly it could just as easily be lactose AND casein AND whey causing us problems. Lactose will feed the gut's klebsiella population, while casein and whey stir up immune response when escaping from a leaky gut into the bloodstream.
However none of those 3 explain why cream is worse; cream has lower concentrations of lactose, casein, and whey compared to milk
http://nutritiondata.self.com/facts/dairy-and-egg-products/51/2so there is probably yet another factor involved. Cream is mostly milkfat; it has a huge amount of fat compared to milk, around 20 times as much fat in heavy cream as in 2% milk. So one possibility I can think of is that the fat in your cream is hard to digest, and is messing up your digestion which will make you worse. I've heard ultra-pasturization makes dairy hard to digest, so perhaps you would do better with fresh cream from a neighbor's cow, etc. Or maybe your digestion of fats in general is not so effective for some reason, and the amount of cream you experimented with had enough fat to overwhelm your system.
