Help - constipation

I had IBS-D prior to surgery and now, since surgery, am constipated.  Oatmeal used to be a trigger but now it's a godsend.  I have celiac so I buy gluten free.  Oatmeal along with Culterelle (any probiotic) seems to do the trick for me.  My doctor wrote an article on the use of probiotics after weight loss surgery.  

Someone asked about prune juice. I have done juice cleanses where you drink 2 cups (!!!) of prune juice every morning.  It does move things through and make you really cleanse.  BUT, if you are already constipated, it can just cause you to have a bunch more that wants to come out, but that is stuck.  So, I think prune juice is a maybe.

I love love love a product called "lower bowel formula" by the brand name Dr. Christopher.  It is an herbal formula that has been around for decades. When I am constipated, I take 6 tablets at bedtime.  It always works, even when other things do not.   It is not habit forming.  I buy it on Amazon. The is also a liquid tincture version, but I prefer the pills.