They say prevention is better than cure, so for beginner hikes, especially dayhikes, how can one try to ensure that their bowels are empty and they won't suddenly need to poo? Are there proven ways? Is taking medication and relying on it bad?
Okay, we a all adults here (I hope) and our bodies have a regular internal rhythm which they are accustomed to deal with. This point is well brought out in James Jenkin's answer.
Recommending medications or even laxatives is a bad solution to this hygienic problem. I would hate to have someone get sick or ill at my recommending something of this nature. Leave that option to professionals such as one's general practitioner (doctor).
All said and done, I like @Aravona's comment: try taking "orange juice, coffee, etc..." Here is why I am saying that this comment is bang on.
I do landscaping for a living and I get up at 4:00 AM every morning. I do not have the luxury of just going to the washroom whenever I want at a job site, but apart from the unexpected (and they will arise) I find the following trick quite useful.
Each morning I start my day with two cups of coffee (one can use orange juice, tea or whatever). I drink then fairly close together time wise and well before I need to leave the house. This puts pressure on your lower bowels, making it a necessity to go and empty the bowels of their contents. Will this methods work for everyone I cannot say, but for me it works quite well.
Happy Trails and not Happy Trials!
Bring toilet paper and a shovel, exercise is a recognized method of increasing bowel motility (making you poo).
Other than planning for the likely need, there are no reasonable medical measures you can take that will have a positive influence. There are things you can take, but for occasional use, the results are unlike to give the results you desire.
Do keep in mind that many people empty their bowels on a fairly regular schedule. If you normally do it at 8:00 AM, you probably don't want to start on the trail at 6:00 AM. Many trails have facilities at regular intervals. Try planning ahead of time, so that this is conveniently done at your normal time which is also a good practice
You can take laxatives, but as mentioned, it can lead to dehydration. You can remedy that by drinking water, which will cause the lesser unpleasantness of having to urinate. The big problem here is that you don't know when the laxative is done working. Residual gurgles in the belly will have to be kept - or maybe not...
On the other extreme, you can take a constipant - the medical equivalent of sitting on a cork. The problem with this method is that if you get sick from the food you eat, you rob your body of the natural function and defense mechanisms it has to dispose of that which is offensive to it. You'll then have to expel by way of vomiting, and this is far worse because of the means and reasons for the expel.
I think, then, the preferred method is to properly learn how to make the arrangements. You need at least three things: a scoop, toilet paper... and knowledge. The rest you'll find along the way.
Personal hygiene is an important factor in your comfort as well as your safety. It's equally important to fellow hikers' comfort and safety as well.
I recommend the internationally-acclaimed book, "How to Shit in the Woods":
While we're on the topic, you might want to take a gander at these books as well:
The books are legitimate, I promise. "Up Shit Creek" is more of comic means to discuss a difficult subject, but all three books are on the up-and-up, despite the name. We have all three books in our scout library.
Now, moving on:
The goal on a hike is to build a "cathole". It's a hole. You dig it with the plastic shovel or scoop. Dig it 6" deep, and 200' away from any water source (actual distance depends on state laws, the most restrictive seems to be 200' in the US). You want to dig down deep enough so that others won't step on it. Also, so that people won't smell it. And also, so that insects like flies won't drag their feet in it, and then park on your ham sandwich.
Next, you do your thing. When done, use a stick you find in the area, stir it around (this helps mix the bacteria-laden soil with the feces, which helps to decompose it faster).
Next, you bury the waste and toilet paper in the hole. When you bury the hole, be sure never to touch the plastic shovel with anything in the hole; you don't have the means to easily clean it.
Next, leave a stick standing in the ground - this warns others to find a different spot.
Last, be sure to use hand sanitizers.
You buy one of those anal enema devices. It's like a soft rubber ball with a little tube on it. You fill it with water and squirt it up your ass. Your body will then react like if you had diarrhoea, and empty the bowel.
Repeat the process a couple of times. The more water you squirt in, the further up the cleansing will go. Also, holding it in for a minute will help it go up further.
When I use mine, I sometimes don't poop again for 48 hours, depending on other factors. And it wont dehydrate you. On the contrary. Any water leftover water in the bowel will be absorbed.
Completely safe and healthy, no chemicals, no medications, no constipation.
Great question because it’s the reason I’ve stuck to short hikes only. I’m reviewing for my RN licensure exam so will respond addressing the medical aspect:
The no laxative / no enema solution - Put your feet up on a 6’-8’ stool while sitting on the toilet. This gets your bowel anatomy lined up for a clear shot out of the exit. Then grab a book and sit for a bit.
Laxatives – All five types have differing amounts of negative effects: Interfering with absorption of calcium and vitamin D, iron, fat-soluble vitamins or other medications; dehydration; lazy bowel syndrome (bowel will not function without them).
Enemas - “Retention enemas” stay in the bowel for 15 minutes (water-based) to 30 minutes (oils). Adverse effects are fluid and electrolyte imbalance, bowel spasms/cramping, and perforation. While routinely doing enemas is not recommended the following are some tips to avoid adverse effects: Repeat water-based enemas no more than once (reduces risk of electrolyte imbalances); warm solution to slightly warmer than body temp. by testing on inside of wrist or 100 – 105 F; slowly administer solution (reduces cramping); position left side-lying and/or knee-chest to distribute the solution throughout the lower intestinal tract; lubricate tip of applicator; and insert tip as if going toward the umbilicus (belly button) no more than 3-4’ (reduces risk of perforation). The key is to keep the solution retained as long as possible for desired effect. Be near a bathroom for when the solution can no longer be retained. Be ready to run! :-) (Fundamentals of nursing, p. 1316-1321, 1331-1334)
Reference: Taylor, C. R., Lillis, C., LeMone, P., & Lynn, P. (2011). Fundamentals of nursing: The art and science of nursing care (7th ed.). China: Wolters Kluwer Health.
For a hike you need energy which needs to be balanced with emptying your bowels. I would try to get my system to empty out as much as possible beforehand as recommended in other answers. One to three days in advance you can eat lots of fibers, e.g. oatmeal and the like. Then stop this around 24 hours before the hike and then eat high energy foods with little fiber. Extreme examples would be olive oil and maple syrup/honey + some protein powder. You will then have tons of energy, relatively empty bowels so you can go for quite a while. And you don't need medication. For the hike, you can bring food that is similar to what you ate the last 24 hours to keep even longer but for longer hikes I recommend that you get used to doing it outdoors - you can get quite nice views! You might want to experiment with exactly what you eat, maybe you need some wheatgrass powder, turmeric or other nutrient packed, non-filling foods. Good luck!