I saw an answer on this site for how a person should be noheg when it comes to tefilah (if he is leaking fecal matter sporadically, he should make sure to have a clean diaper just prior to starting tefilah.) How should such a person be noheg with regards to birkat hanehenin and limud hatorah? (Each change takes 10-12 minutes, and normally would not change unless there is a smell or at a set time)
The answer that you saw was referring to davening, regarding brachos and learning, which are done throughout the day, he should check himself once in a while, not too often. Then as long as he doesn’t smell anything, and isn’t sure that there is something there, he can rely on this to say brachos and learn.
Piskei Teshuvos 75-8.