It is simply the study of pits. Of course, a pitlologist must pick a field to specialize in (e.g., watermelon pits, BBQ pits, or the study of pitiful situations and puns).
When I grow up I want to study pitology since I'm so good at falling into them. I'm going to study pits in the Amazon, Aztec ruins, ancient Buddhist temples, and various tombs in Egypt and India.
The study of pigs/strong interest within several pig related subjects, such as;
Pig fetish
Pig physics Etc.
(looking at quaint piggy)
confused enthusiast: wtf, it's got pig physics
Albert Einstein: I have been working on the problem of pig physics *hands over study*
confused enthusiast: ah thanks now I understand pigology