My Cat CJ had that
He was on daily medication and only ate special high fiber food
Be very careful and monitor bowel movements closely, even with a high fiber diet and medication CJ took mega poops every 3-4 days and it stressed him out, keeping his box clean was critical
Make sure you have lots of water available for the patient, most of the medication tries to keep things moving by keeping them soft so CJ drank a LOT because the medication was using the water
Get your vet to monitor the kidneys, when CJ passed it was due to Kidney Failure, I was told that the medication for his Mega Colon was hard on Kidneys
and sometimes caused stones.....

If you don't get enough information here - try this group (Atheists' Cats) [m.facebook.com]
As Atheists they don't usually spout woo and they're helpful.

I know I've heard the condition described but I don't know the remedies.
Can I ask what the two meds are? I am wondering if it's treated like human conditions.

Add a photo of your cutie and they'll love you for life!

I have never heard of that. It seems to me that there are more chronic ailments being diagnosed in companion animals all the time. I don’t know where you live, but I would definitely explore functional medicine veterinarians in your area. I’m a firm believer that the majority of problems in humans and animals can be traced back to diet and the numerous pesticides, herbicides and fungicides commonly used on the raw ingredients in processed food. I would definitely try as much as possible to feed him organic. I wish you well in this journey with him. You may very well become a wealth of knowledge for others.

I discovered Juliette de Bairacli Levy on Food Matters TV. After watching a documentary about her, I found her book on Amazon and ordered it. There’s a wealth of knowledge in there, and I have used some of her herbal remedies on my cats with great success. Just a suggestion.

If you can manage to keep fiber in his diet, that could help against constipation. Some cats will take to pumpkin (unfortunately not mine though).