Without going into too much detail about my own digestive system, I want to share something that makes my multi-day outdoor outings much more enjoyable. One of the many great outdoor innovations (debatable) of our time is the freeze-dried, just-add-boiling water backpacking food. It is light, easy to prepare, pretty tasty, etc. But like most food you find today, one thing freeze-dried food lacks is fiber. Most people get the majority of their fiber from vegetables and some fresh fruits. In the mountains, however, it is difficult to take fresh fruits and vegetables. Vegetables generally don't have enough calories to be worth their weight and bulk to carry. Fruits are usually heavy and sometimes hard to keep from spoiling or getting smashed. Combine this with the fact that many foods that are great for the mountains, especially during winter (proteins and fats, like cheese, meats, etc), often have the opposite effect of the fruits and veggies, and you have a recipe for, at the least, discomfort, and at the most, digestive disaster (which isn't pretty on multiple levels).
Last year, while camping at Ingraham Flats on Mt. Rainier, our group was sharing a camping area with a guided group of about 15 people. Of course, while camping on a glacier, there aren't too many places (one, to be exact) to go to do your business. That one place is right out in front of everybody. So, when you walk over to, well, you know, you simply inform everybody that you're dropping your pants and everybody else turns around (hopefully). I don't know about you, but I enjoy my privacy while #2ing. So, I hope, when I get over to take care of business, it goes quick and clean and nobody sees anything. Well, imagine (figure of speech, probably not worth really imagining) you just hiked up to Ingraham Flats (or 14 camp, or any other glacier with other people), you have to go to the bathroom, you've eaten a lot of cheese and other calorie-rich, fiber-poor foods, you haven't been able to eat many fruits or vegetables, and there are people around. In your head you're praying that the whole process takes less than 30 seconds, but you know that's not likely. Bad situation. You'd probably almost rather hike back down to Camp Muir to use the solar toilets.
Ok, so when you're in the mountains and not on a glacier and it's time to find some privacy, maybe it's not as big of a deal to keep it under 30 seconds, or a minute. It is, however, much more enjoyable when the process is clean and comfortable. It makes hiking more comfortable, cleaning up leftover bathroom supplies easier, etc. A nice, comfortable two-zy can be quite an enjoyable process, especially if the view is good. It's a nice change from staring at the wall of a bathroom.
A poo with a view, Avalanche Canyon, Tetons
Digestive health is simply a small detail that nobody talks about that can make a trip more or much less enjoyable.
In order to minimize my bad outdoor bathroom experiences and take full advantage of potential good experiences (i.e. good views), I do what I call, "Metamucil Therapy." The idea is simple. About a week before the trip, start taking metamucil. Don't go overboard, but be consistent. Make sure your digestive system is working well. Then, when you get into the mountains, keep taking it. You may need to up the dosage a little to get the same desired effect as you did at home with a healthier diet. Metamucil is not like most other laxatives on the market. It doesn't cause diarrhea (at least it shouldn't). It's bulk-forming and softening. That's why I use it instead of other fiber supplements while in the mountains. And it tastes better than a lot of other fiber options, in my opinion.
It's a good idea to try it out before your trip. It may take some time for your body to get used to it and there's a small chance that it just won't work well for you. But if it does work, what a great outdoor skill to improve. I use this system on pretty much every trip I go on that is over more than about 2 days. It has allowed for consistent sub-30 second bm's, which is key when other people are around and there's no escape to seclusion.