I appreciate the question. Let me go in this way.
There are pancha pranas in our pranic subtle body - prana, udana samana, apana and vyana and each prana has its own functions. Like apana vayu is concerned with the expulsion of body wastes in the form of sweat, urine, faces etc. and the function of SamÄna vayu is to aid digestion. These pranas do not only work in our annamaya kosha (food sheath) but also at the cellular level. A cell consists of three parts - cell membrane, nucleus and cytoplasm. The membrane separates the cells' external environment of nutrients, from its internal environment which consists of cytoplasm and nucleus. Nutrients have to get through the membrane and once inside, the cell metabolizes these nutrients and turns them into the energy that fuels its life functions. And needless to say, every metabolism results in waste material which is required to be eliminated out for optimum functioning to prevent from cellular toxicity. So, here in this picture of cells, Prana refers to what nourishes the cell as well as the action that brings it in and its complementary force, Apana refers to what is eliminated by the cell as well as action of elimination. So, as we adopt mudra based on panch-pranas, the respective pranic force is activated to accelerate its respective function.
By using the combination of two mudras, we get benefits of both the mudras.
When we use apana mudra and samana mudra on both hands, we acquire benefits of both the mudras in apana saman mudra. Samana mudra which is also called mukul mudra (joining tips of all the fingers and thumb) is meant for healing any part of the body as well as improving the digestive system and balances the metabolism and doshas. Apana mudra is a combination of agni, akasha and prithvi elements. Combination of these elements improves digestion and provision of calcium and vitamins. So, by using these two mudras of apana and samana, we are activating the assimilation of nutrients and elimination of waste products out of the body, - nourshing and cleansing at the body level as well as pranic level.
I think it is more or less similar to pushan mudra which in combination of both the mudras - apana and prana - influences the pranic currents that are responsible for absorbing and utilizing food, as well as helping with elimination. Pushan mudra intensifies breathing and therefore the absorption of oxygen and the release of carbon dioxide in the lungs. It has relaxing effect on the stomach, liver, spleen and gall bladder because of effects of prana and apana activation as well as regulates energies in the autonomic nervous sytem, mobilizes energies of elimination and detoxifies. As you said earlier, it has also good effect on general nausea, flatulence and that sensation of fullness one feels after meals. But meals should be 50% solid, 25% liquid and 25% empty.
Both appears to be similar, except in pushan mudra, there is nourishment of prana at pranic level whereas the one later combination you have referred to, aids in complete assimilation and holistic way.
I see that nausea is related to indigestion or any digestion issues and this is worked upon by mudra at the level of prana. But the root cause is dietary habits which if rectified can solve the problem of nause and in that mudra will accelerate the treatment of nausea.
In nutshell, here are some potential benefits of Apana Samana Mudra:
- Improves Digestion: Apana Samana Mudra is said to help regulate digestion by stimulating the digestive fire or Agni in the body. It can also help to relieve digestive problems like constipation and bloating.
- Balances Energy: By balancing the Apana Vayu and Samana Vayu energies in the body, Apana Samana Mudra can help to balance overall energy levels and promote a sense of calm and grounding.
- Reduces Stress: Apana Samana Mudra can help to reduce stress and anxiety by promoting relaxation and calming the mind.
- Boosts Immunity: The practice of Apana Samana Mudra is said to boost immunity by improving digestion, reducing stress, and balancing the flow of energy in the body.
- Promotes Healing: Apana Samana Mudra can help to promote healing by improving circulation and energy flow in the body, and by supporting the body's natural healing processes.
It is important to note that while Apana Samana Mudra may have potential benefits, it should not be used as a substitute for medical treatment or advice. It is also important to practice mudras under the guidance of a qualified teacher and to be aware of any contraindications or precautions related to specific mudras.
I hope the above answer suffice. However, for any further clarification, you may please feel free to write.