A 19-year-old man presented with acute severe ulcerative colitis. He was taking azathioprine (therapeutic metabolites) and sulphasalazine as well as infliximab with a therapeutic drug level. On day 3 of hydrocortisone therapy, he met day Oxford criteria with >8 bloody stools per day and was given faecal microbiota transplantation and subsequently commenced on dietary therapy combining several strategies-(1) increased intake of fermentable fibres, (2) reduced intake of overall and sulfur-containing protein and (3) restriction of sulfate and sulfite food additives. At week 8 assessment, he was in clinical and endoscopic remission and remained in clinical and endoscopic remission at 12 months.