loosing my wonderful mum

mum is 69 and was diagnosed with alzheimers after a brain scan in2002.  mums illness has rollercosted over the last 12 months.  although myself and my dad had tried so hard to keep mum at home, what with her agression and sleepless nights getting worse and with dad almost at breaking point realised this awful illness had begun to turn another chapter.  mum is at present in respite care for 2 weeks and we have had to make the heartbreaking decision to start to look for a care home.  mums behaviour seems to have got worse at respite , she wasnt incontinent while at home but has been in more ways than one since she has been there. does anyone have any advice why this is so.  we worry that when we manage to find a suitable care home because of  being found of a morning a couple of times dirty that a dementia care home wont allow her there.   this illness is so cruelly taking my beautiful mum day by day.  please help with any advice