Always Bloated and Rushing to the Bathroom? Irritable Bowel Syndrome Caused by Phlegm-Fluid

In modern medicine, the abdominal discomfort attributed to phlegm-fluid—particularly irritable bowel syndrome—is recognized as a complex systemic condition rather than an isolated intestinal issue. At its center lies the gut-brain axis. The digestive tract contains millions of neurons and numerous neurotransmitters, functioning as a second brain. During stress, hormones such as cortisol secreted via central pathways alter gut motility and barrier function. Conversely, disrupted bowel states can feed back into the central nervous system, contributing to low mood or anxiety. The concept of phlegm-fluid impairing bowel function corresponds closely with modern findings of gut dysbiosis and chronic low-grade inflammation. When harmful microbes outnumber beneficial bacteria, intestinal mucosal permeability increases, resulting in leaky gut syndrome. As undigested food particles and bacterial toxins cross this compromised barrier into the bloodstream, they induce a systemic inflammatory response and disturb the autonomic nervous system, heighten gut sensitivity. Over 90% of serotonin is synthesized in the gut. When the luminal environment is destabilized, serotonin production and signaling become erratic, driving intestinal peristalsis into hyperactive cramping or sluggish transit that manifests as pain, diarrhea, or constipation. Concurrently, mucosal mast cells release inflammatory mediators such as histamine during stress or food intolerance, directly sensitizing visceral pain pathways. The traditional framework of phlegm-fluid aligns with these modern models of gut-brain axis dysregulation, microbial disruption, and low-grade mucosal inflammation.