Ayurveda is a holistic science. In ancient ayurvedic literature anatomical knowledge about body was describe in all ayurvedic Samhita like charak Samhita sushruta Samhita. They provided important anatomical information.
Guda is a part of distal alimentary canal. Importance of guda in Ayurveda describe as a mahamarm because it is an important part of the body.
The systemic anatomical description of guda is not available in Ayurvedic literature. But we can get an idea about anatomical concept of Guda by taking into consideration of scattered in different texts like charak Samhita sushruta Samhita and asthang hardiyam and almost all concept is easily correlated with anatomy of rectum and anal canal described in modern anatomy.
[gu+da] =to give, overall meaning is the organ which gives faecal matter.
(Definition of guda)
Guda is the organ or opening which excretes mala (faeces) and flatus (apana vata).
Embryo logically Guda is supposed to be originated from matruja bhava of garbha.
The Antra, Guda and Vasti of the foetus are formed from the best parts of blood and kapha, after being digested by pitta and vayu.
E. Location Of Guda
Charaka has classified guda among one of the fifteen kostangas.4
He divided guda into two parts i.e. Uttara guda and Adhara Guda. Chakrapani says that uttara guda is an organ in which purisha (faeces) is collected while Adhara guda is meant for the excretion of faeces. According to Sushruta, it is attached to sthulantra (large intestine) and is one of the organ in relation with vasti.5
While describing operation of Asmari, Sushruta has instructed that first surgeon should intrude his finger in the guda fix the calculus to make prominence in the perianal region. It indicates that guda is located closely posterior to vasti.6
G. Length Of Guda7
Sushruta and Vagbhatta have mentioned that length of guda is four and half angulas.
The measurement of one angula is approximately 2 cm. So we can say that total length of the guda may be 9cm. It is well known that maximum length of anal canal is 4cm. Thus the extent of guda includes the anal canal and lower six cm of rectum which extend roughly up to inferior Houston’s valve. Length of ano-rectum from the anal margin to the recto sigmoid junction is approximately 16.5cm. Out of this 4cm is the length of anal canal upper 7 ½ cm is rectum is included in large intestine by Sushruta. Hence this 4 ½ angulas length of guda exceeds the anal canal and fall short of recto sigmoid junction. It infers that guda includes anal canal and a part of rectum.
H. Internal Structure Of Guda7
Sushruta described that interior of guda consists of three Valis. These are Pravahini, Visarjini and Samvarani. These are circular and are situated one above the other at an interval of 1.5 angual. They are arranged in spiral fashion (sankhavarta nibha) and resemble the colour of palate of an elephant (gaja talu).
Approximate Modern Term
Middle Houston's Valve
Inferior Houston's Valve
Vagbhata has clearified the position of these valis, the proximal one is Pravahini, the middle one is Visarjini and distal one is Samvarani. Gudosta (anal margin) is situated one angula away or distal to Samvarani. Pravahini situated most internally 1 ½ angula to Visarjani and Visarjani situated 1 ½ angual above the Samvarani
I. Vascular Aspect Of Guda8
Sira (veins) represents as a carrier channels of vata, pitta, kapha, blood, lymph, urine, faeces, semen and menstrual blood. Sushruta has mentioned that 8 siras supply to guda, medra (penis) and the sroni (pelvis).
The dhamanis (arteries) taking a downward course carry apanavata, mutra (urine) purish (faeces) shukra (semen) and artva (menstrual blood) to the respective organs such as Pakwashaya (intestine) kati (waist), guda, vasti and Medra.
These all organs are situated below the level of nabhi (umbilicus). The two dhamanis attached to the sthulantra perform excretion of the purisha.