Is there a connection between your efforts on the mat and what goes on in your GI tract? (I know...so poetic).  Here, four registered dietitians who also happen to be registered yoga teachers explain the connection.

Bodily awareness.  Relaxed focus.  Clear intention.  These are all components of a well-executed yoga session - and mindful eating.  With such little research focused on the digestive benefits of yoga, I turned to four of my RDN/RYT colleagues for some insight.

Kathy Brown, The Yogi RD

From my experience, yoga helps to facilitate healthy digestion in 2 ways (there are probably more, but this is my experience):

1. Facilitating that mind-body connection. Regular conscious movement of the body can help to release stress and tension in the body, which in turn can lead to improved digestion.  When the body/mind are under stress, the sympathetic nervous system takes control and leads to the fight or flight response and stopping blood flow to the digestive system to increase blood flow to the muscles, lungs and heart.  Yoga can help to relax the body/mind, which then allows the parasympathetic nervous system to take control and allow blood flow to the digestive tract and work on absorption/digestion of nutrients.   
2. I have also found (in my own journey as well as several students/clients) that a regular yoga practice can lead one to make healthier food choices.  This is not a scientific study by any means, but I have seen more and more people begin to love and respect their bodies just from practicing yoga.  Over time, this has led them to begin making healthier food choices due to their increased awareness of how the food that they eat is affecting their body.

Kate Campbell, Island RD and Yogi

Yoga is about being aware and mindful, and doing things with intent.  Regarding the Hatha part of yoga (the physical poses), two common sayings are "how you do anything is how you do everything," and "your mat is your mirror."  Basically saying how you mentally approach yoga - lazily? focused? calm? do you quit easily when a pose is challenging? Are you rushing to get through or distracted thinking of other things?  Are you comparing yourself to other students, or judging others? - can reflect how you approach challenges and daily tasks in life, including your eating habits.  Are you focused on your food? Or rushed and distracted?

Christin Chan Hebron, The Scarlet Pepper

It was just over 10 months ago when I was pregnant. I remembered that constipation became an issue during my third trimester due to increase in hormones and the pressure of my belly against all my organs. As the baby takes up space and pushes up my intestines, I found digestion to be much slower. I was constantly feeling bloated. Although I practiced yoga regularly throughout my pregnancy, I didn’t think yoga was helpful specifically in constipation and digestion. Yoga was more helpful in the aspect of bringing blood flow throughout my body to help decrease fatigue and cramps. However, I don’t think yoga is a quick-fix. It is something that needs to be practiced regularly in order to receive the maximum benefits.

Mandy Unanski Enright, Nutrition Nuptials

Digestive Benefits:

I started seriously practicing yoga over 4 years ago.  I began attending classes at a hot studio, and the first week I remember that my digestive health was significantly improved and helped to normalize due to the movement and breathwork. 

Yoga & Mindfulness: 

I always bring it back to the breath.  Sometimes we take the fact that we breath automatically for granted, but the fact is breath (or prana) is our life force.  When we bring focus on to our breathing, everything slows down a little and we become more peaceful and mindful.  The same goes for eating, which is something else we can take for granted and get caught up in the moment of eating a meal.  But during a meal, when attention is brought back to the breath and what we’re doing when we’re eating, we start to slow down a little and begin to notice what’s happening.  We remember to chew our food, taste the flavors in our mouth, and give some time to enjoying the sensation of eating.  

Postures for Constipation:

Anything involving twists help stimulate the digestive tract and promote peristalsis while massaging the digestive tract.  As a general rule, we always twist on the right side first, then the left, to follow the path of our large intestine.  Seated spinal twist, or spinal twist on the back are great postures. 

There are also several poses that promote pushing on the abdomen to help stimulate movement.  These include child’s pose, wind relieving pose (aptly named!), forward bend, standing forward bend, prayer squat, and plough pose.

Inversions help increase blood flow and oxygen delivery - shoulder stand and headstand have several modified variations that are equally as effective as the full postures.

Backbending Postures- help elongate the torso and stretch the stomach to get digestive tract moving. Poses include bow pose, bridge, camel, and full wheel.

Pranayama - breathing exercises.  Anything to help calm the mind.  Easiest is to bring attention to the space between the brows (often referred to as the 3rd Eye), and bring the focus there while slowing down the breath.  A good practice is to try to match the length of exhales to inhales. This will help to bring the nervous system into a Rest and Digest period by relieving tension in the blood vessels and nerves.  Typically the end of any yoga session is savasana (“corpse pose”), which is a rest period after the practice to let the body embrace the work and changes that occurred.