If you practice and constipation is still an issue, that means the body hasn't doesn’t meet the requirement of Qi movement.
If you practice Qigong and constipation remains an issue that means your body hasn't met the Qi requirement to change.
Think of the Lung and the colon as twin brother and sister. They work together. If the colon cannot function well, the Lung cannot reach its full potential. One depends on the other for support.
If you're thinking, I don’t see the results. Elimination is still a problem, then take a look at your Qigong system. Does it meet the requirement for change? Have you put in enough effort to effect a change? Quality and quantity will determine your outcomes.