I experienced a similar sensation accompanied with excruciating pain a few days after takedowm; the uncontrollable urge to bear down & pass what felt like a golf ball sized object but nothing would come out.
On the advice of the Hospital Pouch Nurse, I applied ilex Protectant Paste just to the inside of my anus, which instantly alleviated the pain and within a matter of hours the uncontrollable urge to open my bowels also ceased.
However, on the ilex packaging and tube, it does state FOR EXTERNAL USE ONLY, although I've applied it in such a manner with no adverse effect during the last 3 years, other than alleviating pain, discomfort and anal itching.
Doctors never actually provided a convincing reason as to why I experienced such a sensation, although, they did claim it was due to two different skin types meeting; one not being use to the acidic output etc.
Some weeks later, I discovered that during my takedown procedure, my back passage was dilated; I believe it was this which created tiny rips (fissures) to the skin within, which were aggrieved by the acidic output, thus causing the pain and golf ball sensation.
I've never experienced such a sensation since, although from time to time, I do experience anal fissures, which can be excruciatingly painful during a BM and quickly alleviated by the application of ilex, applied internally.
