I would seek a new doctor if I were you. Either that, or stop seeking advise on these particular issues. Our son's doctor told us the same thing - just give him Mirilax every day. We did that for over a year and came to find out that Mirilax has a chemical close to that in anti-freeze. You can achieve the same thing with healthier alternatives.

We consulted a nutrition therapist, Judy Converse, and she helped guide us through the GFCF diet process and supplements. The kid's supplements you get in stores are not nearly enough of what our special needs children need. The transformation in his language and aggression is astronomical. You can read her book if you want to learn more "Special Needs Kids Eat Right." It was very eye opening and scientifically based. We also had urine and stool tests done to really understand what was going on in his gut, it also proved to my husband that what Judy was telling us to do was the right course. It may help your ex understand as well if you have hard data. He still only poops every 3 or 4 days, but is not constipated. I know Judy does phone consults. Not cheap, but so totally worth it!

I hear more and more about how our guts are directly tied to our brains - one doctor even called our digestive system as our second "brain."

DD's Early Intervention preschool required a note from our general pediatrician before they would implement GFCF there. Our pediatrician was supportive of trying GFCF, but she did want us to wait until all the lab tests were done before changing the diet. So if you're planning on doing any lab tests, you'll need to get those completed before going completely GFCF.

We paid a lot of money to get both children tested and they had no issues with Gluten or Caisin so we never went for the change in diet. They both do have issues with constipation if we do not do anything. We regulate them both with apple juice and fruit and it works 90% of the time. If it really gets bad we do use Miralax but have found that if we keep on top of it it does not get to that. It takes time but once you know your child's reactions you can be pretty accurate without Miralax.

Our daughters school is big on research and spends more time and money on it that any other school in the country. And they will not use diets without hard data proving they work. They also do not use suppliments unless tests come back that Warrent them. They have a big success rate in working with ASD children and are one of if not the best in the country so I trust them. The strides they have made with working with our daughter are amazing and they have done it all with proven therapies and a staff that is the best of the best.

Not being negative on the diets because in some cases they are needed because the child has a real medical issue however most do not fall into that category. I suggest having the tests done and if nothing is found do not spend the money on the diet because it is expensive if not really needed

*hug* The Miralax thing is a slippery slope. I have yet to meet someone with a kid that has similar issues that has been on it short term. I refuse to put my kid on that junk. The long term side effects are not well known and there are some disturbing links to neurological issues. I tried the GFCF diet and found that GF didn't make for any changes but going CF had a huge positive impact on the GI issues. It's going to be hard and you have to give it some time (months) before deciding on whether it has any sort of impact but as long as your child is getting a balanced, healthy diet it won't hurt to give it a try (although it will be a big pain in your butt until you have a few good recipes sorted out!). Like what everyone else said:
If you are going to get labs done, get them done first. You can then have them redone after and compare.
Find a supportive Dr or at least one that won't make you feel like crap for disagreeing with you on a treatment choice.
Try going CF and GF separately. If you do it together and you have good or bad results you'll never know which one was responsible.
Give yourself a break, it's going to be tough in the beginning until you find all the CF/GF grocery replacements and have a few good CF/GF recipes that everyone likes and don't cost a fortune. Plan on cooking a lot more.

She's right. It's expensive and makes it difficult for family gatherings, school, and b-day parties. If you decide to continue, I can let you know some of the things I've done and GF foods that I've found that actually taste good. Believe me, if I hadn't seen the results of the urine test, I wouldn't have done it - it sucks!! Of course eliminating caisen too made it even more difficult.