Two weeks ago, I had a laser surgery to treat minor anal fistula and my doctor says it is successful. Two days later from the surgery, I had diarrhea and mucus in the loose stool causing severe rectum pain. My doctor prescribed an anti biotech (Zinnat) for 5 days, but pain continued, then he advised me to change to Flagyl 400 (three times a day) for one week. The pain little receded but still present (It lasts like 2-3 hours after defecation and then disappears) as well as very loose stool. There is no blood in it. I conducted stool analysis and the result showed the follows: Pus cells: 0-2/hpf - Red Blood: 0-2/hpf Cyts Nil - Ova: Nil - Fat Globules: Nil - Undigested food: + - Yeats Cells: +++ . I feel strong rectum and low back pain after defecation with the feeling that I want to extract more. I always feel pulse in the lower area surrounding the anal opening. I dont suffer from any abdominal pain at all. Extremely minor pain fr few minutes in the left lower abdomen. I hope you kindly advise as I am quite terrified I might have an malignant disease.