Cologastric Inhibition: Upper Gastrointestinal Dysfunction With Slow Colonic Transit.

Introduction: Upper and lower gastrointestinal (GI) dysfunctions frequently coexist, potentially mediated by gastrocolonic or cologastric neural reflexes. This study aims to assess the prevalence of impaired gastric accommodation (GA) and delayed gastric emptying (GE) among patients with slow colonic transit (CT), dyssynergic defecation (DD), and to evaluate relationships between CT or DD with impaired GA and delayed GE.

Methods: We reviewed records of 178 adult patients at Mayo Clinic (2005-2025) with documented slow CT or DD (respectively based on scintigraphy and high-resolution anorectal manometry [ARM] and balloon expulsion [BE]) who underwent ^99mTc-SPECT measurement of GA and scintigraphic GE of 320-kcal, 30% fat egg meal. Slow CT was defined by geometric center (GC) at 48 h < 2.1 for males and < 1.9 for females. Abnormal GA ratio was assessed as reduced < 2.62 or increased > 3.85, and delayed GE % < 75% at 4 h. Correlations were assessed using Spearman rank test.

Results: Reduced GA was found in 23.7% with DD and 26.7% with slow CT, while increased GA was observed in 30.1% and 24.4%, respectively. Delayed GE was present in 20.5% DD patients and 35.6% slow CT patients. GC 48 h and 24 h were positively correlated with GE% 4 h (Rs = 0.279, and Rs = 0.294 respectively, both p < 0.001) suggesting slow CT retards GE. GC 48 h was moderately correlated with resting anal pressure (Rs = 0.259, p < 0.001) and negatively with the rectoanal pressure gradient (Rs = -0.166, p = 0.027). No significant correlations were observed between CT and GA.

Conclusion: Slow CT is associated with slower GE, suggesting cologastric reflex inhibition, but not with GA. There is a high prevalence of impaired GA and delayed GE in slow CT and DD.