Determination of the meaning of the term Pakvashaya .

: Pakvashaya is mentioned as main sthana of vata dosha. Basti is called as ardhachikitsa in ayurveda . It works on Pakvashaya . Thus this study is helpful to know the exact sthana of Pakvashya .


Introduction:
Pakvashaya is described in different adhyayas for different functions like digestion, sthan of mutrotpatti, vata dosha sthan. So there is confusion about its exact position. How it works? Due to these queries the present subject is selected for study. This study also helpful in Nidan point of view as well. We come across many patients of Atisar, Sandhi shool, Malavstmabh etc. We can think in those patients about Pakvashaya dushti. This study also helpful in Chikitsa point of view since our Acharya mentioned the action of Basti Dravyas also takes place in Pakvashaya. Thus present study is carried out to observe the Anatomical and Physiological study of Pakvashaya to determine the exact position of Pakvashaya in our body.

Aims and Objectives:
In Ayurveda there is description of Pakvashaya but it is not clearly defined still there is confusion about the term. Hence my aim is - To define term Pakvashaya as described in various classical texts and references. Also with the available data of X-ray, sonography, or colonoscopy the anatomical and physiological study is done to determine the exact position of Pakvashaya. Here according to this, Purishdhara kala is distributed in Amashaya and Pakvashaya. Charaka has described Amashaya as lÉÉÍpÉxiÉlÉÉliÉUÇ eÉliÉÉå UÉqÉÉvÉrÉ CÌiÉ xqÉ× iÉÈ | AÍvÉiÉÇ ZÉÌSiÉÇ mÉÏiÉÇ sÉÏRû Ç cÉÉ §É ÌuÉmÉcrÉiÉå || cÉ.ÌuÉ.
Observation: Physiological considerations: 1) Normal physiology-X-ray-In above normal abdominal standing x-ray, there is gas shadows under diaphragm which indicates the ascending, transverse, descending colon. In Ayurveda, Pakvashaya is considered as mula sthan of Vata dosha. Thus we can see vata in normal abdominal x-ray. Then this area can be considered as Pakvashaya. Colonoscopy-Normal colon Typical folds and vascular pattern can be seen.
2) In Abnormal X-ray or colonoscopy of abdomen shows most of cases shows anatomical change in bowel size & shape or physiological changes. Charakacharya mentioned in Purishavaha strotodushti lakshanas that there is atidrava, atibadha, alpa alpa mala pravrutti, sashool mala, atibahu mala. Instead of these lakshanas we get more symptoms like pain in abdomen, sarakta Drava mala pravrutti. Sthana of purishavaha strotas is Pakvashaya and sthul gudam. Thus in such conditions we can consider it in Pakvashaya dushti.

2) CADAVERIC STUDY:
AS sushruta mentioned, sthan of Pakvashaya is below nabhi. Here an attempt is made to find the structures located below nabhi. Also, Sharangadharacharya mentioned the sthans of all ashayas. Thus here an attempt is made to compare it with that reff. In cadaveric study, an attempt has been made to see the sthan of ashayas as mentioned in Sharangdhar samhita. He mentioned vatashaya is present below agnyashaya & till (gall bladder) and below it there is malashaya. Also one reff from Sushruta that Pakvashaya is present below Nabhi. Thus attempt has been made to see the structures below nabhi.

Discussion:
We have discussed this entire work in following ways-Discussion regarding the literary information collected from Ayurveda and Modern sciences. Discussion based on physiological study observations. Discussion based on observations done during cadaveric study.

Sthan nischiti
Discussion regarding the literary information collected from Ayurveda and Modern sciences. The chime that has reached to the Pakvashaya is already digested . i.e. Digestion is complete before it reach to the Pakvashaya from Grahani. And no further digestion takes place in it. Only absorption of the water and formation of gases takes place in Pakvashaya.

Anna-Parinaman
The content in the form of mala is Paripindita meaning the content is haustrated/Saculated.
Thus we can explain digestion in Pakvashaya in following ways-Inegsted food is having a label as a food still the amla avasthapaka. whether it may be apakwa (amavastha) or pakwa (pacyamanavastha), after that food is completely digested and converted into sara bhaga and kitta bhaga. Sara bhaga flows into rasavaha strotas and further dhatu parinaman takes place. On the other hand kitta or the waste product reaches the unduka and formation of purisha takes place with the help of purishadhara kala and maladhara kala. The purisha is then gradually pushed towards guda. During its pathway, shoshana of the watery materials takes place by the local agni and resulting into the paripindita form of purisha. This is the place for the katu avasthapaka. The paripindita purisha is eliminated by the help of apan vayu. The absorption of water and electrolytes, maintenance of bacterial flora, and absorption of nutrients these function indicate the vivechan carried out by influence of saman vayu. The evacuation of mala is under the influence of apan vayu, is the other function. After the Grahani, there is Pakvashaya, half digested food retains some time in the Pakvashaya, and kala is responsible for the absorption of water and electrolytes and maintenance of bacterial flora. While peshi is responsible for Munchan of the kitta i.e.remainig after the digestion. The maladhara kala and purishadhara kala is confined as internal portion of unduka and Pakvashaya. As the functional difference between the proximal colon and distal colon is concerned, the proximal colon internally consists maladhara kala and distal colon consists of purishdhara kala. So the proximal portion absorbes water and electrolytes maximum, which lined by the maladhara kala. The distal portion stores the purisha and evacuates with the help of apana vayu, which lined by purishdhara kala. Pachaka pitta, saman vayu and apan vayu are the main responsible substance for the functions of Pakvashaya.

Conclusions:
Through the past few pages as attempt has been made out to put the theorotical consideration of Pakvashaya sharir and its relevant Vikruti.
On the basis of literary review and physiological study following points are concluded-Pakvashaya starts from kshudrantra and ends in rectum (malashaya). As proximal half of the colon concerned with absorption and distal half with storage, the term Pakvashaya can be used for Large Intestine.