Fiber side effects. These complications?

I had a fistuletomy surgery 35 days back. Before surgery, i never had any constipation problem. I used to defecate 1 or 2 times in a day, and the stool was soft. I had no problem with defecation except the fistula symptoms. But after surgery, on doctor advice, i started consuming a lot of fiber products such as fruits, vegetables, prunes, and naturolax. My stools were bulky and normal in the first few days, but i used to have stomach bloating and gas from day 1. After a few days, gradually, i started developing more problems such as bloating, stomach cramps, farting, burping, stomach noise, 6-7 times defecation. I started feeling incomplete after every defecation, and the stool quantity is less each time. Also, while defecation, i pass a lot of gas and little stools which causes bleeding from the wound. I visited m y surgeon and he said my wound is clean and healing well. He advised to stop naturalox and gave Meva-C. Is excess fiber the reason for all these complications?