Yoga is a practice that incorporates movement, stretch, stillness, and breathing to open the bio-energetic and neuronal pathways in the body.
Each form or stretch is geared to nourish and bring blood to a particular organ.
Breathing and stillness allows you to control the autonomic nervous system-which controls heart rate, breathing, and digestion.
There are forms in yoga that are specifically for the digestive system. These forms help the movement of food through your body, and aid in elimination of waste.
Daily movements and forms of yoga for the digestive system has shown great reduction in constipation according to research.
Yoga is low-force, low-impact, and can be done at your own pace. However, IT IS NO SLOUCH of a fitness program. It takes discipline and hard work!
Some use yoga and meditation together or have religious practices they incorporate. That is up to the individual. I have seen patients who use yoga only for the physical and visceral (organ) strengthening aspect.