How Long To Fast To Clear Bowels

Update (1/16/20). I have done another water fast, this time for 20-days: 20-day water fast blog post.

This past holiday season I underwent an extended 13-day water fast. During this fast I eliminated all foods and liquids from my diet – except for water. When I told my friends and family about this, one of the first questions I usually got was, "is there a specific reason why you're doing this"? The main reason I was interested in performing a water-fast was wanting to give my body a rest and allow it a chance to reset and recuperate. I am no stranger to fasting – I have done 8- and 5- day water fasts in the past, but this was indeed my longest one undertaken. I won't go into the specifics, but there are many studies that show benefits of extended fasting on both improving the immune system and even extending healthy living. Before the fast, I also was practicing intermittent fasting (IF) – here is a great resource if you are interested in IF.

Although a superficial effect of a water fasting is weight loss, I will not be focusing on this aspect – I did not perform it for this reason. Additionally, I am not a proponent of using water-fasting for weight loss, unless you have already made the long-term changes that allow for a healthy life. Yes, water fasting will allow for short-term weight loss, but what is more important are long-term lifestyle and nutrition changes that will allow for a healthy body and for you to achieve whatever your ideal weight is. Without, long-term lifestyle changes, the weight will undoubtedly return once the water-fast is finished, and then you'll be back at the point you were trying to distance yourself from in the first place. This will cause more harm on your body than good. Again, water-fasting alone is not a sustainable weight-loss method. Long-term nutritional and lifestyle changes are the important areas, extended water fasting is for allowing your body to rest, heal, and renew itself – weight loss is just a side effect.

My water fast was strictly water – no Himalayan salt, tea, coffee, vitamins, minerals, supplements, enemas, lemon juice, apple cider vinegar, or anything other than water. I have a personal water filter at home and drank from that, except for bottled water while I was travelling. I did not buy any specific alkaline or distilled water.

During each day of the fast, I wrote a log on how I was feeling and how the stages of the water fast were going. Below are the logs, I hope you find them useful as you may have similar experiences if you do an extended water fast:

Day 1:

"Today was a good day". Since I had been eating in a window from around noon to 8pm for the past month, I was comfortable going most of the day without food. I did have a few bouts of hunger in the evening, but they easily went away after drinking water.

I didn't notice any energy change on the first day and my mental clarity was normal. Since it was the holidays and I was taking some time away from work, I didn't have any experiments I was doing or deadlines to worry about.

This day I was travelling out of town; a woman at the airport sat next to me and started eating some type of sandwich and it smelled quite good. My thoughts about food at this point were not an issue and I could easily think of other things. I did not have any bowel movements today – and I usually have at least 2 daily. Overall, the first day wasn't bad, but do keep in mind, I am used to fasting.

Day 2:

Today was more difficult than day 1. The last meal I had before the start of the fast was a well sautéed salmon and green beans I had at a restaurant for my grandmother's birthday, and I kept thinking about it. My thoughts raced about how delicate it was, and how it melted in mouth. It did make me hungry but mostly only in the evening.

My energy levels were good, I woke up earlier than usual and without my normal alarm. I did a lot of reading and contemplation on what my goals for the new year would be. During my contemplation, I had an optimistic outlook on what I would manifest in the coming year.

I did not have a bowel movement at all today. However, I did drink lots of water and urinated quite frequently. My body felt good and my body composition is starting to noticeably look slightly different.

Day 3:

I slept for about 10 hours last night and woke up with a headache. When I woke up my body also felt noticeably tired and achy.

About halfway through the day I felt much better and the headache subsided. I wasn't too hungry today and didn't think about food much. My energy levels we're okay, although I did just lie around and relax most of the day.

My mind wondered a lot today, but not as much as the previous day. A large focus of my thoughts were on a book I was reading about left/right brain hemisphere learning. I began thinking about how to best utilize my own learning styles to help in accomplishing my goals.

During the evening I had a boost of energy lasting for about 3 hours. But as the night approached, I had slight discomfort in my head and it began to hurt. I relaxed the rest of the evening.

I urinated regularly and it was mostly clear. Still no bowel movements. I drank lots of water.

Day 4:

I woke up after only 5 hours of sleep and I felt great. I had lots of energy this morning and my mind was racing with thoughts.

I had the strong urge to go outside and just meditate – so I did. Although I drank lots of water the night before, and even some throughout the night, my urine in the morning was yellow-brownish.

My energy levels throughout the morning were amazing. I had no hunger and felt great. I went swimming and walked around a lot during the morning. I was not thinking about food, and urinated frequently throughout the day. Still no bowel movements.

I did not have any headaches throughout the day and had a pleasant feeling in the morning and afternoon. During the afternoon I told myself, "hmmm, if every day felt like this, I could do 30 days easily" – maybe in the future!

I flew home today, and while I was at the airport waiting for my plane to board, I rested my head in the waiting area, and I fell asleep. Next thing I know, one of airport staff came and woke me and telling me final boarding was happening. On the flight, the family seated directly behind me began eating some type of fast food. The smell was alluring, it's almost as if I could taste the MSG on my tongue.

At around 4:30pm this day, I had my first bowel movement. It wasn't very much, and it was a greenish color. Perhaps from a green shake/smoothie I had the day before the start of my fast.

Later on that night, I had a second bowel movement. It looked similar to the previous one: greenish.

Day 5:

I woke up this morning a little later than usual. My energy levels were not as high as the previous morning, but still I felt good. I still had an optimistic feeling about the fast and was looking forward to working on a few small things now I was back home.

I did some work in the morning and found my focus and problem-solving ability seems heightened. I did not have much hunger and when I drank water any hunger feeling I had immediately vanished.

Halfway through the day I began to feel fatigued. I took a nap around noon and when I woke up, I felt a slight achiness in my upper body and arm region.

After my nap, I forgot to stand up slowly, and tried to stand up right away and felt lightheaded. I had to lay back down, sit up on my bed and then finally stand up.

In the late afternoon I went for a walk around my neighborhood. I could feel I didn't have my normal energy during the walk, but it was still able to enjoy the walk.

I was walking around inside my condo and I went to the kitchen and subconsciously opened the refrigerator. There was nothing in there I needed, but it's almost as if I did it out of habit. I immediately realized what I had done and closed it right away.

I stayed up later than I usually do. I was working on a project and I didn't want to stop working on it. No bowel movements this day.

Day 6:

I slept well last night and woke up feeling good. During the morning I had a bowel movement.

I had a good amount of energy in the morning and had a strong desire to take care of a few errands I had been putting off. I had a good mood today and felt positive. No hunger, just thirst. My mouth/tongue did have a weird taste (most likely keto breath) but nothing too bad.

I had another bowel movement late afternoon. It was more volume than the previous times, but still the same greenish color.

I went to get my annual car inspection done today and, while in the waiting area, one of the staff offered me some bottled water. It was cold (out of the refrigerator). I usually like my water room temp, but for some reason this chilled water was very pleasant.

I noticed I seemed to have excellent mental clarity and was able to recall things quite well.

Day 7:

I woke up this morning feeling good. My heartbeat felt a bit off, but it soon passed as I got up and drank some water.

I went for a walk around my neighborhood in the morning, and I could feel that I did not have as much energy as usual. Breathing wasn't necessarily difficult, but I was much more conscious of my need to do it.

I did some errands and felt optimistic all throughout the day. In the evening I focused on a project that was mentally taxing, but I made incredible break throughs on it and had been struggling with making progress on this task for a while – weeks.

After working on the project, I felt fatigued and went to go lay down. I was tired earlier than I had been the past few days, so I took it easy for the rest of the evening.

I did go to my kitchen and out of habit open the refrigerator again. I still had no reason to open it, but it was almost as if I didn't even realize what I had done until after the act.

No bowel movements today, but lots of urination.

Day 8:

I woke up this morning feeling a bit achy in my body. I slept well but did have a dream where I was at the laboratory I work in and I couldn't find a certain research specimen I needed.

I felt a bit more lethargic today but still had an intense drive to accomplish things. My stomach did a little bit of grumbling and at times. It felt like hunger, however, once I drank water it quickly subsided.

In the afternoon, I decided to take a walk to a nearby university library. I usually ride my bike their (or drive), but I didn't feel up for cycling there. The walk was about 40 mins, and it was more strenuous for me than anticipated. By the time I got there, my heart rate was elevated, and I had to take a moment to sit down and recuperate. I was walking at a leisurely pace and the hills I encountered were minor and few.

At the library while I was recuperating, I fell asleep in one of the chairs. On the walk back home, I felt better. As I was walking, I called my mom (who knew I was fasting). We started talking about how I gravitated towards unhealthy foods when I was a child – my nutritional skills were quite bad when I was younger, especially in high school. I felt a cramp in my arm while I held the phone up during our conversation.

I felt a slight tingling in my left leg behind my knee. I had been having some issues with this area, especially after extended running or intense leg workouts.

Later that night, I began meticulously planning out the nutritious post-fast meals I would eat. That night, I did have a bit of stomach growling. No bowel movements.

Day 9:

I woke up this day feeling good. I went for a walk in the morning and it went well.

At around 2pm, I crashed hard and had to go lie down and take a nap. After the nap I felt better.

I did start visualizing and thinking about foods, but it mostly all non-processed nutritious foods: broccoli, salmon, salads, fruits.

I was researching a lot online about foods and how to best adjust my diet to naturally obtain all the vitamins and nutrients strictly from food intake.

Day 10:

I woke up this morning and laid in bed for about an hour just reflecting on life. I could feel a tiredness in my muscles, but it went away after a while.

I had a bowel movement later in the day. The stool seemed to be coated in a mucus-like substance. It was not as green as before but more of a brownish-green color.

I walked to the nearby farmer's market and bought a plant. My energy levels were good, but I did feel a bit tired in the afternoon when I got back from the farmers market. I sat and read for a little and felt more energized.

My mental focus was good, and I had spurts where I was able to accomplish multiple different tasks with great efficiency.

Day 11:

Today I felt great. I woke up with lots of energy and was exceptionally happy no apparent reason.

In the morning shortly after I woke up, I had a bowel movement. Again, it was covered in a mucus-like substance and had a reddish color to it.

I noticed there were small rash-like areas appearing on the skin of my back.

I got a full body massage later in the evening. During the massage I could feel the difference in my muscles and there was a tenderness/soreness I experienced during the massage when certain muscles and areas were pressed.

I did have a few thoughts about food, but it was anything too strong. And mostly about what foods I would be avoiding after the fast. Later in the evening, I started thinking about eating salads and about what kind of fruits and nuts I would put on them.

Day 12:

I felt great this morning. My nose was a little runny, but I didn't feel sick.

My body was still sore from my massage the day before, especially in my back. Although my stomach did some rumbling in the morning, my hunger was not noticeable.

My body temperature did seem lower than usual and I turned the heat up a few degrees to be comfortable.

I felt I was more adapted to the fasting and I could feel the difference now compared to the previous days. Especially as I walked around my neighborhood.

During the late evening before I went to bed I had more thoughts about salads and all the different types of salads I would make when I ended my fast.

Day 13:

The gym I go to opened back up today from the holiday break, so I decided to go to work out for the first time since the start of the fast. I did very a reduced workout – very basic. It was mostly just light exercises with body weight as I didn't want to use any heavy weights in case I passed out. I also did some walking on the indoor track there too.

I set an alarm today so I could make it to the gym when it opened at 6a. For the previous days of the fast I did not use an alarm and allowed myself to wake-up unassisted. When I woke up, I felt good and even though I was purposely waking up a bit earlier, I did not feel tired. However, when I returned from the gym a wave of exhaustion swept over my body like a sandstorm. I decided to take a short nap and felt better when I awoke.

After my nap, my mind was racing with ideas and I immediately went to go write them down. I felt colder and had to turn my heat up even further to be comfortable.

I had originally planned on going 14 days, but by the end of this day I decided it was time to end the fast.

Breaking the Fast:

I had some spinach and grapes to break my fast. The grapes tasted especially sweet. About an hour after I ate, I had a bowel movement. That night I went to bed but woke up extremely early. The next day I ate a lot of fruits and vegetables blended up.

It is now two days after breaking the fast as I am typing this. I feel great, my mood is positive, and I feel relaxed and rejuvenated. I have decided to slightly rework my nutrition to increase the amount of vitamins and minerals I am receiving and will be slowing incorporating workouts back into my daily post-fast routine.

Takeaways:

Although not the first, this was the longest fast I have attempted thus far. After the first few days it was not difficult. I was off from work and had told my family I would not be partaking in any holiday meals beforehand. I also did somewhat of a break from technology and emails – allowing me time to fully focus on myself and my body.

The mental clarity I experienced as a result of this fast was well worth it, and although I did not get any testing or blood work before the fast, I do feel healthy. As I mentioned at the beginning, I was not doing this fast for weight loss and do not recommend using water fasting as the major focus of a weight maintenance strategy. If you are already in a lifestyle and eating a diet meant for your body, you will either already be at the natural weight you are supposed to be at, or your body will instinctively adjust to reach that weight over time without fasting. Water fasting while still having an unbalanced nutritional lifestyle before or after the fast will cause an undue amount of mental stress causing you to likely rebound binge after you finish fasting – this will diminish any benefits you received and may make things worse. The mind can only handle so much, this is why it is a good idea to have an exceptional grip on your lifestyle and nutrition before attempting something as drastic as a water fast. With that being said, I did lose a significant amount of weight; I am opting not to share how much since I do not want the focus of this post to be centered on weight loss.

Overall, I enjoyed the experience. Having the time off work was beneficial, as I could foresee having project deadlines and experiments to perform on some of the days that I felt tired, would have been a difficult undertaking – though not impossible. If you have any questions or want to share your own water fasting experience, please feel free to leave a comment below!

Update (1/16/20). I have done another water fast, this time for 20-days: 20-day water fast blog post.

-Tyler

Tyler

A scientist, public speaker, and writer living in Raleigh, NC. He works as scientist at Duke University researching cell biology, cancer health disparities, and how cancer spreads (metastasizes) in the body.