Qsymia + constipation?XD Anyone else go through this? >>

I'm weaning myself off of qsymia (well really topiramate and phentermine).
But I realized it's been about a week since my last BM and I've been having a lot of pain in my abdomen. >0<

I have two 3 hour flights tomorrow so I was wondering if there was anything that I could take after I land that would work asap? o_o


edit: And I have been drinking TONSSSS of water the last week especially. I will fill up my 32oz cup 5-6 times in a day. But it's also hot as heck here (105F) and I've been doing a lot of house and yardwork so yeah >>