There are already several definitions for this term on here, but all of them are wrong.
I think
people must be confusing "hard fart" with "dense fart", and those terms are not the same thing.
A "hard fart" or "hard
gas" is a medical term, something you might tell your doctor or your doctor
may ask you about. A hard fart is a painful fart that sometimes has to be squeezed out to relieve pressure in the bowels as a result of constipation. You
will discuss this with your doctor as a symptom of constipation. Usually, there is no defecation associated with a hard fart because of an underlying constipation issue. Sometimes a
small amount of solid particles or "fecal debris"
may pass along with this fart leaving skid marks, but this is not the same as a "
shart".
Conversely, a "dense fart" comes about as a result of a diarrhea issue, usually a precursor to blowing mud. Hard farts are a precursor to having a painful,
dry bowel movement sometime (often days) later.
Doctor: "How often do you have bowel movements?"
Patient: "About every 4-5 days, but I have a
lot of hard farts for a few days prior to having a
BM."