Chronic Constipation In Toddler

Hello. I am really hoping that someone might have some advice to help me. I have a 16 month old son who suffers from chronic constipation. His constipation began at 6-7 months of age and has worsened over the past 8-9 months. He screams and cries when trying to have a bowel movement and goes days and days without any activity. Oftentimes, the screaming and crying will result in one small claylike stool. He has been on Miralax since 7 months of age. He is on a pretty large dose these days and it really seems to have lost most of its effectiveness. We have tried Lactulose but no success. We have been under the care of a Pediatric GI specialist who has ruled out anatomical abnormalities (obstruction, blockage, etc.) or pathological causes (Hirschprung's, Celiac, etc.) of his constipation. As parents, we are at the end of our rope. We are trying so hard to help our little boy, but these days, nothing helps. We have tried the high fiber diet, he eats PLENTY of fruits and veggies. His two favorite foods are fresh pears and freshly steamed broccoli. We have taken him off dairy and he drinks rice milk. He isn't the best water drinker, but we are diligent and can probably get about 6 oz of fresh water in him daily. Since rice milk is 88% water and he tons of fresh fruit and veggies, we think he gets enough water. He has several VERY wet diapers during the day too.

At this point, we are considering a colon cleansing product for our son. Has anyone tried a Colon Cleanse for a young child? Was it successful? Is there anything that I should know in advance? Are there any product recommendations?

Thank you for any advice you can offer!

uvagirl1996