By Dr. Rita Khanna
I think not many of us know much about our digestive organs. We all know about our heart and lungs, but we pay little attention to our stomach, since it takes lower priority in terms of fatal attacks. However, we definitely attack it with wrong eating habits, over eating, lack of activity, and exercise.
We only care about it when there is a colicky pain, abdominal discomfort, hunger, or loss of appetite. That is why so many people today are suffering from digestive disorders of one sort or another. A basic understanding of the digestive system, and body maintenance, is important in the quest for better health.
PROCESS OF FOOD DIGESTION
The body has two holes – the mouth and the rectum. Between them is a hollow tube which stretches from end to end, uninterrupted in its continuity, except for odd valves interspersed between the many sections. When food particles are ingested, they must be digested, absorbed, and assimilated. This transformation is aided by secretions of the stomach, liver, gall bladder, and pancreas. How the food reaches the cells is described below:
• Ingestion: Food is taken into the digestive canal through the mouth, pharynx, and esophagus.
• Secretion and Digestion: Enzymes, acids, and other chemicals, are secreted for the breakdown of food into smaller particles. This process starts in the stomach and continues into the small intestine.
• Absorption: Water and small soluble units are absorbed in the small and large intestines.
• Assimilation: Food is transported, via the bloodstream, and utilized by the cells of the body.
• Rejection: Undigested particles are expelled from the rectum and anus. This process also removes poisons from the body confines and is part of the general process of cleaning and assimilation that goes on continually.
POINTS TO REMEMBER
• The whole process goes on continually, without a break, until all the food ingested is assimilated and all the wastes are disposed off. The process is thus a smooth-flowing continuum, and each part is dependent on the other parts for its efficient functioning.
If one step goes wrong, the whole process is disturbed, and a vicious circle of bad health results. For example, when the digestive juices are not flowing, in a balanced and regulated manner, assimilation and absorption cannot take place. The whole organism is so integrated and dependent on its parts, that if one part is not working, the whole body suffers.
• The nutritive properties of food depend not only on the quality, but also on the way in which it is prepared, and the atmosphere in which it is eaten. Thus, food prepared with the important ingredients of care and love, contains a great deal of Prana and energy, and gives life to the body.
One’s mental attitude to the food is also of great importance for good digestion. Thus, try to visualize in yourself this structure – passing from end to end, like a pipe, with the rest of the body wrapped around it.
JOURNEY OF FOOD

MOUTH
Food enters the mouth, and the process of digestion begins. Within the mouth – the teeth, palate, tongue, and salivary glands all function together to make the food into a bolus – a mushy lump which will travel neatly into the stomach. The salivary glands secrete a substance containing the enzyme called ptyalin, which breaks down starch and neutralizes acids in the stomach. Saliva is secreted at a rate of one to two liters per day. Therefore, the process of digestion really starts in the mouth.
POINTS TO REMEMBER
• It is important to chew your food properly and make use of saliva and the enzymes it contains. This is the first step to proper digestion and health.
• If the body is not hungry, then the mind and brain do not trigger the digestive juices to function. Therefore, eat only when you are hungry.
• The sight and smell of food causes our digestive juices to flow, especially when it is something which we really enjoy eating. When we are hungry, we enjoy our food more. Hunger is determined by a drop in the blood sugar level. This produces contractions of the stomach wall, which last about thirty seconds each. These ripples are called ‘hunger pains’.
• If we are tense, or the chewing is inadequate, the juices will not flow properly. Therefore, do not eat if you are tense or when you have been rushing around.
• Once the food passes from the mouth, it is usually forgotten, unless we cultivate yogic awareness and try to follow it through the many different channels of the body.
• Avoid excessive indulgence, if you want to tread the path of Yoga and good health.
ESOPHAGUS (FOOD PIPE)
The esophagus starts in the throat and ends in the stomach. It is made of muscles. There are no bones in it. It is about 25 cm long and allows the food you swallow to get to your stomach. The swallowing process is quite complex, and involves the movement of the tongue to throw the food into the esophagus, and the cutting off of the air passages, to prevent food from passing into the lungs. Next time you swallow, close your eyes and try to follow the movements. Become aware of exactly what happens in this common, but usually unconscious, process.
STOMACH
The food pipe ends in the stomach. The stomach wall is thick. The food is churned and digested by the acids and enzymes secreted by the stomach wall. There are two types of stomach movement taking place during digestion:
1. In the stomach wall, muscles exert a steady and slight pressure, which squeezes the food towards the opposite end of the stomach – called the pylorus. This movement pushes the food stored in the upper part of the stomach towards the lower end, where it enters the small intestine.
2. A vigorous contracting movement mixes and churns the food, with digestive juices, and pushes it into the duodenum – the first part of the small intestine. The gastric juices include hydrochloric acid and enzymes – such as pepsin, lipase, rennin (to break down milk), protein, and fats. The stomach secretes hormones, such as gastrin. It also secretes gastric mucin, which plays an important role in the protection of the stomach wall from chemical, microbiological, and mechanical damage. This substance prevents ulcers forming on the wall of the stomach.
POINTS TO REMEMBER
The stomach is about the size of your hands cupped together. To fill the stomach, we need to eat no more than this quantity. However, the stomach can stretch to enormous proportions to accommodate the sometimes enormous amounts of food we deposit in it. For optimal digestion, fill the stomach with one third solid, one third liquid, and one third air. Food stays in the stomach for two to six hours, depending on the type of food consumed.
Fats, and non-vegetarian food, are harder to digest than other protein foods and carbohydrates. This is why a vegetarian meal gives more energy and does not create a feeling of fullness or heaviness. When we eat a big meal, more blood is drained from the brain and other vital organs to the stomach, for greater periods of time, than a light, small meal. Thus, we may feel sleepy after a large meal.
SMALL INTESTINE
The small intestine starts in the lower part of the stomach and knits itself zig-zag in the abdomen. Its length is eight meters, and it is located between the stomach and anus. The inside of the small intestine is held in place by tissues, which are attached to the abdominal wall. The outer side of the wall of the intestine is very delicate. The inner side of the wall of the intestine has hundreds of thousands of villi (hair like projections), which contain blood vessels and lacteals to absorb food. These villi serve to increase the surface area of the absorption mechanism enormously, from 76,000 square centimeters to 4,500 square meters, the size of three tennis courts placed next to each other. Thus, there is plenty of room to absorb nutrients from food.
POINTS TO REMEMBER
We must be sure that the nutrients of the food are accessible to the process of absorption. This means that we must chew our food properly, and with awareness, in order to break down the components. We should also be relaxed to allow the correct concentration of acids, enzymes, and hormones for optimum digestion.
The water we drink enters in to the intestine after about ten minutes, but non- vegetarian diet takes about four hours to enter into intestine. It takes about six to eight hours for digesting the food. The small intestine is the longest section of the digestive tube, and consists of three segments, forming a passage from the pylorus to the large intestine:
• The first part of the small intestines is called Duodenum. It is the shortest segment of the intestine, which is 25 centimeter long, and it starts from the lower end of the stomach. It is roughly horseshoe-shaped, with the open end up and to the left, and it lies behind the liver.
Duodenum receives partially digested food from the stomach and begins the absorption of nutrients. The food is further digested by juices from the liver, and pancreas, which pour down a common bile duct.
The duodenal secretion enters into the blood, and reaches the pancreas, to stimulate it to secrete its alkaline juice and enzymes for the digestion of the food. About one liter of the juice, from the pancreas, enters into the duodenum, in a day, which decreases the acidity of the material coming from the stomach. If it is disturbed, it may lead to ulcers.
• After leaving the duodenum, food passes into the Jejunum, another part of the small intestine. This tube of muscle is two, to two and half meters long; d this part is not really small, but it is thinner than the large intestine, which is short. In jejunum, most of the nutrients are absorbed into the blood.
• It is followed by the four meters long part of the small intestine, which is known as Ileum, where the remaining nutrients are absorbed, before moving into the large intestine.
IMPORTANCE OF THE SMALL INTESTINE
• The food entering into the intestine, from the stomach, contains acid. If such food enters into the intestine suddenly, it may damage the intestine, and it can decrease the digesting capacity of the digestive juices. However, the small intestine converts the indigestible food into the acceptable form, and provides us the elements to maintain life. It can be called as a large food processing plant.
• Through this digestible food, the energy for blood circulation, muscle power, as well as generation of the cells of the body, is obtained.
• Intestines convert lipids (fat) into fatty acids and glycerol.
• The conversion of carbohydrates (notably starch), into glucose, is done by the intestines.
• Even after eating excessively, the special capacity of the intestine manages to keep the person well.
• The intestines digest everything inside the food, except the fibers of the fruits, vegetables, and peels.
LARGE INTESTINE
At the end of the small intestine, there is ileo-cecal valve, connecting it to the large intestine. The length of the large intestine is equal to the height of the person. It starts in the right lower part in the abdomen, at the end of the small intestine.
It proceeds upwards and turns to left, and then proceeds downwards, and ends in the anus. After the digestion is over, the substances, which have not been absorbed in the small intestine, enter the large intestine, in the form of liquid and fiber.
The water is re-absorbed from the large intestine, which enters into the blood and goes to the liver. The liver makes blood from extracted food juice and sends the blood to the heart. The other dirty liquid is sent to the kidneys. The kidneys purify it and send the uric acid to the bladder, from where it comes out in the form of urine.
The remaining unabsorbed materials, such as the skins of fruit and vegetables (mainly cellulose), bile, and intestinal secretions, including mucus, dead bacteria, white blood cells, and cells from the walls of the intestines are excreted by the large intestine. They all get collected in the rectum, which comes out through anal canal.
RECTUM
• Defecation is a complex reflex act. As the passage of faeces into the rectum distends the muscular tube, signals are sent to the conscious and unconscious parts of the brain. This brings about a conscious voluntary decision to inhibit or permit reflex evacuation. If we are relaxed, the process occurs all the more efficiently.
• The parasympathetic system, which is concerned with relaxation of the whole body, allows the sphincters to open and the muscle wall to contract, propelling faeces out of the anus.
• A great many disorders are connected directly to the malfunction of the digestive system. In this way, the digestive system has a direct influence on one’s daily life. You must have noticed for yourself that when you are experiencing digestive troubles, you tend to be pessimistic and easily irritated. Conversely, a healthy digestive system allows one to be happy and free from pain, worry and suffering, to make you cheerful and optimistic.
FOOD FOR THOUGHT
• After swallowing, food takes approximately three seconds to travel from the mouth to the stomach. It takes one to five minutes for the first mouthful to enter the duodenum, and twenty minutes for half the consumed food to leave the stomach. In four and a half hours, it travels from the duodenum to the end of the small intestine. After five and a half hours, the first mouthful has reached the start of the large intestine, the caecum.
The first mouthful of food takes nine and a half hours to reach the end of the large intestine, the sigmoid colon. From start to finish, the complete process of digestion takes from twelve to twenty-four hours.
• Next time you have a meal, try to increase your body awareness by following the progress of digestion in your body. Of course, you will have to remember throughout the day, that the process is going on, but this exercise will increase your awareness.
• Another interesting exercise is to visualize the tubes concerned with defecation, when you go to the toilet. Awareness can be expanded any time and anywhere. There should be no limitations to your awareness, and no psychic blocks or complexes concerning bodily functions.
YOGA AND A HEALTHY DIGESTIVE SYSTEM
A healthy digestive system means energy and vitality; it reflects a positive lifestyle. Yoga is the way to bring about a relaxed, efficient, and harmonious digestive system. It is the key, by which the body systems can be tuned to a state of good health. This includes the nervous system, which co-ordinates such activities as observing the food, and conscious appreciation of it – right down to the last stage where defecation occurs.
YOGASANA FOR THE INTESTINES
In order to keep the digestive system healthy, we must have strong intestines. There are many exercises for the intestines in the form of Surynamaskara, Halasana, Paschimottansana, Shaahankasana, and Yogamudra.
Among all these – Yogamudra is very helpful in regularizing digestion and problems of the gastrointestinal system.
YOGAMUDRA TECHNIQUE

Sit on a mat, on an even surface, in any comfortable Asana. It can be Padmasana, Vajrasana, or Sukhasana. If possible, sit in Padmasana (lotus posture). For Padmasana, bring your right leg over the left thigh, then left leg over the right thigh, sit straight, bring your hands behind the back, hold your left wrist with your right hand, make a fist, and put your thumb inside the fist.
Inhale and stretch the spine. Gently breathe out, and bend forward, till the forehead touches the ground. Keep the eyes closed. Hold the breath outside. It is called, Bahyakumbhaka. Practicing Yogamudra, with Bahyakumbhaka, increases digestion capacity because the blood circulation decreases in the legs, and it is available in the intestine. The blood circulation also increases towards the heart and the brain. There is stretching of the back muscles and massage to the intestine.
If you can’t hold the breath, do normal breathing. Do it for about 20 seconds in the beginning, and increase the time gradually to about five to fifteen minutes, without any fear. For coming up, inhale and slowly lift your head from the ground. It can be done when the stomach is empty or four hours after taking the food. Persons of all ages can practice Yogamudra fearlessly.
BENEFITS
The upper energy of the navel, and the lower energy of the navel, come together in the posture, and then helps in better digestion – it increases flexibility of the knee, hip, and ankle joints – relaxes the neck, back, and arms. Regular practice of Yogamudra gives relief from constipation. indigestion, gas formation, chronic colitis, leucorrhoea, knee joint pain, low backache, and burning sensation in the eyes, which arises from the problem of chronic constipation.
Om Shanti
If you feel inspired by this article, feel free to publish it in your Newsletter or on your Website. Our humble request is to please include the Resource as follows: Courtesy: Dr. Rita Khanna’s Yogashaastra Studio. A popular studio that helps you find natural solutions for complete health.
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Dr. Rita Khanna
Dr. Rita Khanna is a well-known name in the field of Yoga and Naturopathy. She was initiated into this discipline over 25 years ago by world famous Swami Adyatmananda of Sivananda Ashram in Rishikesh (India).
She believes firmly that Yoga is a scientific process, which helps us to lead a healthy and disease-free life. She is also actively involved in practicing alternative medicines like Naturopathy. Over the years, she has been successfully practicing these therapies and providing succour to several chronic and terminally ill patients through Yoga, Diet and Naturopathy. She is also imparting Yoga Teachers Training.
At present, Dr. Rita Khanna is running a Yoga Studio in Secunderabad (Hyderabad, India).
Tags: DIGESTIVE SYSTEM, HEALTHY DIGESTIVE SYSTEM, Padmasana, Sukhasana, Vajrasana, yoga is, yogamudra, yogasana


thanx mam for ur wonderful technique for digestion..
can u tell me about these all asans Surynamaskara, Halasana, Paschimottansana, Shaahankasana,with picture..bcoz i dont no how to do it…
Thanx,,
Hi I love this asana for digestion. Thankyou
Thank you very much DR.
Yogmudra I do regularly.
Please tell and guide about Sirshasana, Mayurasana, Chakrasana.
Please give details about daily balaning food which I take. I’m purely vegiterian.
In the Morning Breakfast, In lunch and in dinner.
My office timing 7.45 am to 7.30 pm.
Hi Dr. Rita,
I want to tell you something,actually i regularly read several type of yoga book,have some knoledge about it..practlly and theoretically.
If you dont mind may i share something to you?
Regards
Amit
Dear Dr Khanna
Your articles are always so inspiring. The depth of knowledge you share inspires me to be a better teacher and student.
Yours faithfully
Gerald*
TAIWAN
Thanks for the informative article. However, no offence, but may I sugest a correction in write up? The article syas that small intestine……….”Its length is eight meters, and it is located between the stomach and anus.” Here the wording instead of “stomach to anus” should be “stomach to caecum” (at ileocaecal valve)From there large intestine starts as is rightly said in the article.
by chewing food “properly” the ‘satiety centre’ in brain is satisfied and naturally the ‘appetite centre’ is de-activated, hence is satisfied with less amount of food. Thanks
Thanks for your vivid and lucid description of intestinal process of assimilation and evacuation.
I love your articles and I read them regularly when I get my newsletter from Aura Wellness Center. I am grateful for you clear, consice and succinct knowledge. Thank you for your gifts. Hari Om, Patty Morale
the article was very informative but have not mentioned when to do and howmuch to do.
I found this article very inspiring and love to adopt what you have suggested and given in your article. Indeed a very nice one. Till now nowhere in yoga classes I have come down such a suggestion as to be aware of what happens after we take food.Awareness and conscious effort which you have given is nice thing to follow.
Thank you.
I add my voice to the thanks for this article – very timely and clear in its explanation – Tracie
Thanks so much for sharing this information. It came at a perfect time! I have been having digestion issues. I have recently begun to pay more attention to an area and fucntion of my body that I have neglected over the years. Bless you!
Anna B