Hi. thanks for your query. Noted the history and understood the concerns. Recurrent incidences of itching and burning in rectal/anal area after bowel movements which get alright with Flagyl momentarily can be due to the following reasons: Recurrent intestinal infections particularly colitis. Peri-anal excoriation or dermatitis due to local conditions, retention of sweat. This can be diagnosed by the following ways: Get the stool tested. Get the blood tested for CBC, sugar. Examination by a General Surgeon or a Dermatologist may help you further to get the proper diagnosis so that a proper management can be done. It may be necessary to have a course of an antibiotic in addition to Flagyl for 5 days and continue probiotics for about 2 weeks. Rarely a colonoscopy and biopsy may be needed if the medical management fails to heal the problem. Local care and hygiene in the form of cleaning with plain water 2-4 times in a day and keeping the area dry and well ventilated helps a lot irrespective of the cause.