Simultaneous data (uroflow, voided volume, and NIRS pattern of chromophore change) in a child with severe symptoms of nonneurogenic lower urinary tract dysfunction. Following permission to void a sharp decrease in [O₂Hb] is evident with a coincident equal and opposite increase in [HHb] (5–10 seconds), while [tHb] remains stable (see similarity in Figure 6, 785–790 seconds). Between uroflow start and uroflow end [O₂Hb] shows an overall downward trend while [HHb] rises further initially and then plateaus. [tHb] rises briefly and then falls reflecting simultaneous changes in [O₂Hb] and [HHb]. The overall chromophore pattern during voiding implies an imbalance of oxygen supply and demand and the potential for muscle fatigue due to oxygen debt.