a couple of things are worthy of trying, as what "fixes" one calf, doesn't necessarily work on another. First, I would switch hay. If already feeding a grass hay, change the type of grass hay. Also, I would add rice bran OIL to his feed. It will also be very beneficial to his coat, and is VERY nutritious! I would also try switching his feed gradually. I'm not knocking your brand of feed, but something is apparently disagreeing with his digestive tract, and "band aids" additives might relieve the problem temporarily, but it doesn't solve the problem.