There is not complete agreement among health professionals about the need to restrict casein or organ meats. Yogurt does contain lactose. But part of the lactose has been converted to lactic acid, so yogurt can be tolerated by some individuals. Some lactose intolerant people may also be sensitive to sugars other than lactose. Remember that people react quite individually to various amounts of lactose in their diet.
Some people have more discomfort from skimmed milk than from whole milk.
Strange as it seems, sweetened milk beverages such as chocolate milk may be better tolerated since the added sugar may slow down release of the lactose from the stomach into the intestine. During the cheese-making process, most of the lactose is drained off with the whey. Only trace amounts of lactose remain. Cottage cheese, also a fresh, unripened cheese, generally has additional milk or cream mixed with the curd. Therefore, fresh cheeses contain lactose and may have to be avoided.