The heat should be comfortable so one should be careful not get burned.
A moxa session for this purpose can take 2-5 minutes and a stick can last several session so this is quite cheap. I find that old moxa is better as it is drier and feels better.
I feel that the best food ingredients are:
1. Dry FIGS - leave in hot water for a minute to clear the FIGS from whatever dirt that may be on the outside and soften the inside. I think that eating one FIG before each meal can have a good effect on the digestion and soften the stools.
2. Papaya - wash the peel well and eat before or between meals. The peel is known to be beneficial for skin burns so I feel it makes a good effect on the bowls as well.
3. I find that moderate spiciness that gives a bit of heat to food (chilli peppers) can also help digestion.
4. Pineapple - this fruit is unique with the enzymes that I feel can help with digestion. I have no experience with conserved pineapple so this applies only to fresh. Since this is so potent, I think that more than half a cup might be too much in one eating.
I believe that once you have fissure, you'll always have to consider it, eat less, make sure you're hydrated, eat the right ingredients and from time to time maintain the sensitive area with moxa and possibly with the cream I proposed in a previous message.