I was juicing then went vegan last year cold turkey (pun intended), took up powerlifting/olympic weight lifting and accidentally swallowed a whole habanero all within a few months of each other. I couldn't remember being constipated and was lost as to what was causing my fissure. I made it a habit to go in the morning and thought maybe I had mild impaction since it was only hard to start but apparently it's okay to go the next day.
I knew my diet was very grain heavy as I was eating mostly rice, beans, potatoes, peanut butter and other thick dry heavy things almost every day when this all started. I would make a batch to have prepared meals ready to go. Vegetables were also in there but while my goal was to have a heavy carb diet, it ended up being a heavy grain diet. My first adjustment was to start using more oil in my mixed rice as I was also experimenting at the time with limiting fat which was creating a perfect storm of "dryness". While the re-addition of fat helped I was still suffering. I began limiting rice to 3x per week max and having pasta/spaghetti, soups, salads and other "moist" foods the other days which only reduced the frequency of pain.
Then after eating a giant plate of leftover spaghetti on an "off grain day" I had trouble starting my B.M. again the next day. I started paying closer and closer attention to the conditions in my environment causing the fissure and ended up focusing more on what is preventing the healing instead. This change in mind helped me realize that it wasn't specifically the exercise intensity since I stopped that activity and have not eaten spicy items yet still suffered which means at one point or another I strained harder than I thought. (Spicy food and exercise will worsen symptoms but are not the cause).
Eventually I realized that my full dependence on my toaster oven was drying all my meals out! This is important for all those that realize the dangers of and abandon microwaves. Now I reheat things on the stove and have mastered the art of re-hydrating leftovers. All my life my mother did this to our food and I had no idea!
After fearing all kinds of other ailments it finally hit me that I'm simply suffering from perpetual constipation and the fissure is merely the symptom. I wasn't listening to my body and wanted to feed it what was convenient and available. So after a year of short painful bouts and a mild sense of not fully evacuating I started eating bananas, drinking water and moving around every morning whereas before I would just go immediately after waking before my body was awake. I rehydrate my meals and try to eat the veggies raw instead of cooked in rice cooker with the rice. Heat was my enemy! I now know why Afghans use so much oil in their rice as constipation is a common problem in the middle east and asia!
The point is none of the treatments on this page will help you in the long run if you don't cure the cause. The solution is to change your diet to be at least 50% moist. This chart I attached is the secret to avoiding fissures forever and will be your daily test on the effectiveness of your diet. Type 4 is your goal.
If you're suffering right now then buy a bag of prunes and a few bundles of bananas. Eat 1 to 3 ounces of prunes (they might say dried but they should be moist/juicy) before breakfast and with your dinner and try to eat 3 bananas a day. It's funny because Type 4 is shaped like a banana too!
DRY FOOD (FOOD NOT REHYDRATED)
GRAIN HEAVY DIET (EAT AN EQUAL AMOUNT OR MORE OF PLANTS/VEGGIES)
EATING FOODS WITH NO OIL (YOU NEED FAT IN YOUR DIET TOO ESPECIALLY IF YOU DON'T EAT MEAT/DAIRY)
Switch your dinner to lunch and eat lunch at dinner. By eating your biggest meal in the middle of the day when your digestion is at its peak your body will have a much easier time with evacuation. Eating at its core is about digestion and evacuation. The faster you evacuate the healthier you will be. I suspect a large portion of people suffering this have a similar extreme diet!
Anal Fissure - Change in diet helps
I had an anal fissure that kept bleeding everytime I did #2. I figured out that this was due to constipation. So I looked for remedies to fix constipations. I found out that constipation can be helped if you add fiber to your diet. So I started eating lots of things with fiber (high fiber cereal), vegetables, beans, etc. I also found out that my constipation might be related to a yeast infection that I had. Yeast infections are caused by candida, which feed on sugar. (You can easily find many anti-candida diets on the internet). So I started to eliminate sugar from my diet. I had the anal fissure for about 3.5 months. After 1 month on the anti-candida/high fiber diet, I am happy to see that my stools are a lot softer and I am not getting anal fissures any more. I am not sure if this is due to the high fiber are the lack of sugar in my diet. Either way, I am happy with my results. I am not sure how long I'll stay on the anti-candida diet. I am thinking at least 3 months total, and I'll introduce a few sweets back slowly. Hopefully my fissures won't return then. I hope my story helps someone.