Dear friend, welcome.
I would support you on early evaluation.
typically alternate constipation
, especially in an elderly,
should be worked up to rule out bowel cancer
not to scare you, but is a concern.
differentials could be many.
at least an ultrasound
of abdomen / pelvis would tell if there is any tumour etc. also labs, and physical exam etc are necessary.
pl. give details of any tests already done.
good luck .. and keep me posted..
would like to answer...