This stuff works extremely well. There is no flavor, no smell and it does a great job.Soluble: susceptible of being dissolved in or as if in a liquid and especially water.This is INsoluble fiber. Incapable of be dissolved in liquid.Therefore, there will be grit.Drink it up! It’s good for y’a bowels!This is a gentle, gluten-free, hypoallergenic product with NO Fodmaps and the best fiber supplement I have ever found for my sensitive gastrointestinal system. I have many problems. A pre-biotic was all Fodmaps, which I am just now learning about because it affected me so badly with abdominal and bowel problems. This wonderful product has cut down on the symptoms and is helping my conditions without medication. It is just methylcellulose powder. Nothing else. Dissolves in water well, easy to swallow.This fiber is essential, and often seems more useful to me than soluble fiber. But, a balance of both is very important in any form of diet, whether from supplements like this and/or from food. The folks leaving bad reviews may not understand the nature of INsoluble fiber. It's going to keep its form, it will be gritty a bit, and it's NOT going to mix well in water. It's INSOLUBLE fiber. Same as in any food, it's what moves stuff through your system like a "broom". It speeds transit. Soluble MIXES and/or becomes gel-like in some cases, slowing digestion, adding bulk to doo doo. Both are useful and needed for normal function. Just understand that insoluble fiber isn't a "mix in water to dissolve" sort of thing. If you drink it fast, or mix it with, say, smoothies or something, it's fine. UPDATED: This has now priced itself out of sustainability for me. I'm now achieving same sorts of results and function buying NuNaturals Oat Fiber, which per ounce, or pound, is much cheaper, I get more insoluble fiber per like amount...AND, with oat fiber, I can bake with it, put it in smoothies, etc.Since Honeyville stopped producing corn bran I've been looking for something with very high levels of insoluble fiber, and here it is! Works great to keep my digestion moving, and it has almost no calories. It doesn't really taste like anything, so you'll want to mix it with other foods to make it taste better, and I wish it was less expensive.I bought a bottle of each of these so I could see what the difference was. Neither dissolves very well in hot water. Both taste slightly gritty with no real flavor. Either can be sprinkled on food or mixed into a smoothie. NutriCology is all cellulose, an insoluble fiber, 250 grams total. It lists 8 calories per 2 gram serving but that is what burning cellulose provides. Since cellulose is indigestible there are really no food calories at all. UniFiber contains 240 grams total but only 180 of that is insoluble fiber calculated by multiplying the 3 grams of fiber per serving times 60 servings. The remaining 60 grams are maltodextrin and xanthan gum. That is what provides the 4 food calories per serving listed on the label. The result is that UniFiber contains only 72% as much insoluble fiber as the NutriCology product. Seems like Unifiber should cost less but when I write this it costs more.I put a tablespoon of this in my smoothie after my workout every morning, along with psyllium husk so that I have both soluble and insoluble fiber. It doesn’t mess up the flavor of the smoothie. It is a bit gritty because it won’t dissolve but really, I like being able to poop everyday so I don’t care. It’s a supplement, not a treat. I will continue to buy.My wife has suffered from IBS for years. This was recommended to us by a friend and the difference in her has been wonderful. I highly recommend it. You have nothing to lose except perhaps some of your problems.I found this fiber easy to use. It goes down easily with a half cup of water. As an insoluble fiber it doesn't dissolve of course but I did not find it unpleasant to swallow. Also mixes easily with food. As someone with IBS-C and SIBO I find it more effective than soluble fiber and did not experience any gas from it. You only use a teaspoonful 1 to 3 times per day so I think it will prove to be fairly inexpensive. Now if only it came in a pouch instead of a plastic container(less waste).