Activia has some special brand of probiotics that are supposed to help the digestive system. I believe they use a blend of these cultures to make it special and unlike other yogurts supposedly. Reality is that it is expensive yogurt. Most yogurt now has live cultures, but you can look on the container for it to say "live and active cultures". Unless your system in incredibly sensitive, it won't matter for the most part which brand you buy. Now some do have more cultures than others, but for the most part any yogurt that has live and active cultures will have enough to help.
The whole activia thing is more a marketing gimmick, from what I have seen. yes, it is a bit different than other yogurts, but not in any way that would make a big difference. You can also get probiotics in other forms - most often in pills or capsules in the vitamin section. Acidophilus is a common and very helpful probiotic that is sold that way. I have used it for a couple of decades because it helps when the IBS gets out of control.
Personally, I live on yoplait orange yogurt. Only one I can stand the taste and texture off. Most yogurts are pretty much the same so look more for what he will actually eat rather than a special promise of something. If the texture of yogurt is a problem, try the Yoplait thick and creamy. It has gelatin added to make it a much thicker, creamier product. Still has the live cultures, still will help things, but is a different texture. I don't know of any other brand that makes this thick yogurt - and I have looked, lol!
Walmart has fourpacks of yogurt and they are live/active cultures and the flavors are the same as the brand name ones. I cannot tell them from the name brands.
Fiber is definitely an important part of handling his problem. It is sort of a cure-all for most digestive problems. If things are too watery, the fiber will absorb the water and help it out of the system. If things are too hard or dry, the fiber will bring moisture from the other areas and it will push things out easier. There are a lot of cereals and other things with fiber. Fruits and veggies are excellent . They make fiber bars now that are sold in the cereal/nutrigrain bar section. The amount of fiber varies, but usually is fairly substantial. Now they come in a 90 calorie size and a larger size that has more calories and more fiber. My kids like the fiber one chocolaate peanut butter bars. they may only come in the 90 cal size, i am not sure. The kids have eaten every other fiber bar on the market though, and they really like almost all of them. He will learn not to pig out on them. thank you was told only one per day but he ate three in an afternoon and spent about three hours in the restroom. He says he won't make that mistake again, lol!
I have also found a surprising, to me, source of fiber for the diet. Our stores sell something called Flatout flat bread. It is like a thicker tortilla, like a homemade tortilla thickness instead of a machine made one. They are quite large and sell in packs of 5 for around $2.50-$3.00. These surprise me because the light ones have more fiber and good stuff for you, not just low calories. One light wrap is big enough to make two meals for me, sometimes three if I have a salad instead of shoving the veggies into the wrap. Each light wrap has 9 g protein and 16 gram carbs of which 9 are fiber. So they have 7 grams of carbs that are not fiber - incredible for many bread recipes. We LOVE the light italian flavored wraps - they add flavor and are really easy to hold. the company now has some other products taht fit in with this, so here is a link:
http://www.flatoutbread.com/products/flatout-wraps/
I hope this helps.
But I honestly don't know what might result. Doesn't that "balance" your digestive system in some way? Would it help his pattern...or at least not harm it. DDD
