From Gut to Core: How Muscle Coordination Impacts Bloating and IBS

Abdominal bloating and distension are among the most common and distressing complaints seen in gastroenterology and pelvic health practice. For many individuals, these symptoms occur without excessive gas accumulation or underlying disease, making them frustrating and difficult to treat. Increasingly, research has identified abdomino-phrenic dyssynergia (APD) as a key underlying mechanism in functional bloating and distension, particularly in patients with irritable bowel syndrome (IBS) and functional gastrointestinal disorders. 

APD represents a disorder of coordination—an abnormal interaction between the diaphragm, the abdominal wall, and the pelvic floor. Understanding this condition through a musculoskeletal and neuromotor lens has opened new avenues for treatment, particularly through pelvic floor physical therapy, where skilled clinicians retrain these muscles to work in harmony again. 

The American Gastroenterological Association (AGA) defines abdomino-phrenic dyssynergia as a paradoxical viscerosomatic reflex.  In response to minimal gaseous distention, the diaphragm contracts and descends while the anterior abdominal wall relaxes—producing visible abdominal distension. 

Normally, when the intestines expand slightly after eating or during digestion, the diaphragm should relax and ascend while the abdominal wall muscles contract, stabilizing intra-abdominal pressure and preventing outward protrusion. In APD, this normal pattern reverses: the diaphragm moves downward, pushing abdominal contents forward, and the abdominal wall yields instead of providing support. The result is an outwardly distended and bloated abdomen, often with sensations of fullness or pressure out of proportion to actual gas volume. 

Research using electromyography (EMG) and imaging confirms this dyssynergic pattern. Patients with APD show increased diaphragmatic activity and reduced tone of the abdominal wall during visible distension, even when gas volume is normal. This explains why some individuals experience severe bloating after meals while imaging shows no excessive intestinal gas. 

There may be multiple systems that help cause APD, including central nervous system dysregulation and somatic muscle dysfunction. The reflex appears to be abnormal communication between visceral afferents (gut sensory nerves) and somatic efferents (motor output to the diaphragm and abdominal wall). 

This miscommunication may be amplified by visceral hypersensitivity—an exaggerated response to normal digestive processes—commonly seen in IBS and functional bloating. The brain perceives normal gut sensations as uncomfortable, and in response, it activates a maladaptive motor reflex that increases diaphragmatic contraction and reduces abdominal wall tone. 

Over time, these maladaptive patterns become learned motor behaviors, reinforced by chronic discomfort, stress, and altered breathing habits. This is where pelvic floor physical therapy and muscle retraining come into play. 

The diaphragm, abdominal wall, and pelvic floor form a dynamic pressure system. These structures work together to maintain intra-abdominal pressure, support organ function, and coordinate breathing and postural stability. 

• During inhalation, the diaphragm descends, intra-abdominal pressure increases, and the pelvic floor lengthens to accommodate this pressure. 

• During exhalation, the diaphragm relaxes and ascends while the pelvic floor gently lifts, helping to regulate pressure and maintain continence. 

When this system breaks down—as it does in APD—pressure distribution becomes unbalanced. A downward-moving diaphragm without adequate pelvic floor and abdominal support can increase intra-abdominal pressure, contributing not only to bloating and distension but also to symptoms such as pelvic heaviness, urinary urgency, or constipation. 

Pelvic floor physical therapists are uniquely positioned to address APD because of their expertise in evaluating core muscle coordination, breathing mechanics, and neuromuscular re-education. Treatment focuses on restoring the relationship between the diaphragm, abdominal wall, and pelvic floor through a combination of manual therapy, rehabilitative ultrasound, and motor retraining. 

The first step is a thorough evaluation of the patient’s breathing patterns, postural habits, and core activation. Many patients with APD exhibit: 

• Upper-chest dominant breathing (shallow, accessory muscle use) 

• Abdominal wall weakness or delayed activation 

• Overactive or underactive pelvic floor muscles 

• Increased intra-abdominal pressure with breath-holding or straining 

Pelvic floor therapists often use real-time ultrasound or manual palpation to assess how these structures coordinate during rest, breathing, and abdominal distension episodes. Educating patients about their body’s mechanics is foundational—many are unaware of the diaphragm’s role in their bloating symptoms. 

Training begins with restoring diaphragmatic breathing, but with an emphasis on proper abdominal wall engagement. Patients learn to allow gentle abdominal expansion during inhalation while preventing paradoxical over-descent of the diaphragm. 

Techniques include: 

• 3D breathing: Encouraging lateral rib expansion rather than excessive downward pressure. 

• Abdominal wall retraining: Teaching activation of the transversus abdominis (the body’s natural corset) to provide anterior support during respiration. 

• Rehabilitative ultrasound: Using visual feedback to teach patients how to control diaphragmatic descent and abdominal wall tension. 

Studies show that consistent diaphragmatic training can normalize breathing patterns and reduce visible distension in patients with functional bloating. 

The pelvic floor should move in harmony with the diaphragm. In APD, the downward pull of the diaphragm can cause excessive strain on the pelvic floor, contributing to dysfunction. Therapists teach patients to coordinate pelvic floor elongation during inhalation and gentle activation during exhalation, using cues like “let the breath drop into your pelvis” or “lift the pelvic floor as you breathe out.” 

This integrated approach not only improves mechanical pressure regulation but also enhances visceral support and proprioceptive awareness—helping patients retrain their body’s internal reflexes. 

Hands-on techniques may be used to release restrictions in the diaphragm, rib cage, pelvic floor, or abdominal wall that contribute to dyssynergic patterns. Soft tissue mobilization, visceral manipulation, and myofascial release can improve tissue pliability and facilitate normal movement patterns. 

In some cases, therapists may also collaborate with gastroenterologists or behavioral health specialists to incorporate central neuromodulators or biofeedback-based cognitive retraining for patients with significant visceral hypersensitivity. 

Because APD can be triggered by meal ingestion and postural factors, therapists often guide patients through functional retraining: 

• Practicing relaxed, coordinated breathing before and after meals 

• Postural alignment to reduce diaphragmatic load 

• Gentle core strengthening for stability without over-bracing 

Patients also learn to identify and reduce behaviors that increase intra-abdominal pressure—like chronic sucking in, shallow breathing, or overuse of abdominal bracing. 

Emerging studies support the use of muscle retraining and breathing retraining as effective therapies for APD. Controlled trials show measurable improvements in abdominal distension and patient-reported bloating severity after targeted respiratory and abdominal wall coordination training. While pharmacologic treatments may reduce bloating perception, behavioral and physical therapy approaches directly address the underlying motor dysfunction—the hallmark of APD. 

Abdomino-phrenic dyssynergia is a neuromuscular coordination disorder, not a problem of excessive gas. By recognizing APD as a learned, reversible motor pattern, clinicians can offer patients a pathway to long-term relief. 

Pelvic floor physical therapy, with a focus on diaphragmatic and abdominal wall retraining, restores the natural coordination of the body’s pressure system—reducing visible distension, improving core stability, and enhancing quality of life. 

As awareness of APD grows, collaboration between gastroenterologists, physical therapists, and behavioral specialists offers an integrative model for treating this condition. 

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Disclaimer: This blog is here for your help. It is the opinion of a Licensed Physical Therapist. If you experience the symptoms addressed you should seek the help of a medical professional who can diagnose and develop a treatment plan that is individualized for you.