Sometimes you need want to describe one noun with another. This requires a transformation of the noun into a different part of speech, ie an adjective.
Terms such as this are typically colloquial and used as parts of comical speech.
Rather than saying "I am having issues with my stomach" or "I'm having stomach issues", the noun can be turned into an adjective by truncating the word and adding "icular" or in some cases simply appending "icular" to the end of the word.
Comparison example: "Vehicle" would become "Vehicular" by truncating the "e" and appending "icular". An example of this would be Vehicular Homicide where one noun becomes an adjective to describe another noun.