Functional Dyspepsia (FD) vs Irritable Bowel Disease (IBS)

What is the primary distinction between Functional Dyspepsia (FD) and Irritable Bowel Syndrome (IBS)?
How is the pain associated with meals in both FD and IBS?
What are the underlying causes and associated factors for FD and IBS?
How does the Rome IV criteria aid in diagnosing FD and IBS?
What are the first and second-line treatments for FD and IBS?
Important highlights from our discussion:

Functional Dyspepsia primarily causes upper abdominal pain, while Irritable Bowel Syndrome causes middle and lower abdominal pain.
FD often results in postprandial discomfort and early satiation, while IBS pain is commonly associated with defecation and changes in bowel habits.
Both FD and IBS are associated with abnormal gastrointestinal motility and visceral hypersensitivity, but the specific factors differ due to the involvement of different parts of the gastrointestinal tract.
The Rome IV criteria, a widely recognized set of guidelines, are used to diagnose both FD and IBS based on a range of symptom criteria.
The treatment of FD and IBS typically starts with lifestyle modifications, followed by specific pharmacological interventions based on the condition's distinct features.