How to prevent constipation after BMX surgery?

Thank you. Do you think some specific diet or bowel prep will work? Sometimes I have 2 bowel movements a day, and still have hard rocks plugging the exit. Sorry for these disgusting details, but my proctologist just says "take care of your bowels" and my GI - "just take fiber". I did not go to GI after he called me in just to yell at me saying that I should not bother him with my hemorrhoids, and just should take fiber.

I ate all-vegetable diet and three servings of beets with prunes a day before surgery, but it did not help much. The suffering next day was comparable to childbirth, and I do not have good memories of my kid being born: I was torn so badly, that a doctor could not figure out how to anatomically correctly repair all the damage (all organ that you can think of down there were torn, too gruesome to describe). I did not want any kids after that experience, and never had them. What also contributed to this decision is my horrific experience of breast feeding: milk got stuck in the breasts. I was running high fever for the first half year. Doctors said to drink less fluids so I would produce less milk, massage breasts, and manually pump milk, otherwise they threatened to cut my breasts open to remove hard lumps. Actually, I think my BC is partially caused by the injury to my milk ducts caused by these vigorous massages that I had to do two times a day for more than half a year. This was more than 25 years ago (in a country that ceased to exist), but I avoided touching my breasts afterwards, they were very   painful for 2 weeks each monthly cycle. I'm sorry for venting, I'm just scared of what future hold for me, and I have no confidence in medical community after what they did to me then and over the next decades. I understand that to treat BC I have to go to them, there is no choice, but more often than not I just want to quit.

I was trying to strike a balance within the last three years. I thought I did, but the surgeries knocked me out of it big time. I can feel the big shift in digestion patterns  practically overnight, after the second one: I could not eat too much raw vegetables before, and, suddenly, I can, without major gas or discomfort. I did a test for gut flora before, and it showed some overgrows of not very pathogenic bacteria. It seems like antibiotics killed this species, and some more, and now I cannot manage . I calculated that I eat  the average  of 40 g of fiber from veggies and flax seed per day. I also drink more than a gallon of water in a hope to help. I'm running out of ideas.

Thank you all. I guess I have to accept yeast infection as a lesser evil, and load up on beets, fruit, and prunes with some stool softener (?).  I guess a stimulant laxative (like senna or bisacodyl ) can be taken as needed. What is your experience with milk of magnesia (magnesium hydroxide) and miralax (polyethylene glycol)? I think these laxative  draws water into  intestines and colon, respectively, but I may be wrong. I never tried them, I also never tried stool softeners either. What about mineral oil? Thank you again for helping me out.

I'm responding now to my own question. I'm 6 days post-op BMX now. This is what I did to prevent post-op constipation. I started taking stool softener 4 days before surgery: first one dose, then two. I went on a diet consisting of boiled chicken, chicken broth, and boiled vegetables (cabbage soup ) two days before surgery. One day before surgery I was on a liquid diet (fresh apple+carrot juice, broth, vegetable broth, water) and one dose of stool softener. No food or drinks 12 hours before surgery. Vegetable soup, pureed apples and carrots at the end of the day after the surgery + stool softener with food. Resumed my diet of fresh vegetable salads, vegetable soups, chicken soups and broth afterwards, took two doses of stool softener a day and Jarrow's Gentle fiber.. Had a bowel movement the day after the surgery, and then every day so far, but I still take one dose of stool softener a day. A cup of freshly brewed diluted warm coffee helped to initiate a bowel movement for me. Magnesium citrate (the "Calm" drink) also worked once, but not as good.  I also have taken two doses of probiotics every day, had some fruit, seeds, coconut butter,  boiled and shredded beets every day after the surgery. I did not take any opioids after the surgery, only extra strength Tylenol, so far.