You are having ulcerative colilis and that has relapsed (recurred) again. Please do not worry to much about it. This disease has variable course i.e it may come after improvement for many months to years. Most important advise is "be in touch with your primary physician (gastro-enterologist) whenever you have recurrence". Restart of rectal bleed, diarrhea
mixed with blood and mucus, abdominal pain
are alarm sign for patient to consult your doctor again so he can modify medicine to achieve improvement. Usually kidney
problem is unrelated to ulcerative colitis
. Discuss same issue with your gastroenterologist.