Dear Dr Toshio Goto,
I use water assisted colonoscopy. I am often stuck at Rectosigmoid junction. I follow your advice for Rectosigmoid junction, but the lumen just does not open up. It takes a long time with jiggling and repeated searching to see the lumen. In the end I am not even sure which particular technique helped me as the results are not consistent and reproducible on another day. I do not have problem at other sections of colonoscopy.


Can you please advise how I can rectify this?

Thanking you

The air method use full of air, so the colon is extended.
It is easy to find the orientation.

The water method use small amount of water, so the colon is collapsed.
Becouse colon mucosa is always close to the scope, it is difficult to find the orientation.
The way to find the orientation in the water method is deffrent from that in the air method.

If you watch the mucosa of the colon, you can see a lot of hairlines, very very small grooves.
The orientation and the hairlines are always right angles.
If you see the hairlines are vertical, the orientation must be left or right.
If you see the hairlines are horizontal, the orientation must be up or down.

When you push the scope to make it go forward, the image of the colon in the moniter might rotate right or left.
But if you watch the hairlines of the colon mucosa, you won't miss the orientation.

https://www.youtube.com/watch?v=4yXoHKNrP2I

https://www.youtube.com/watch?v=TVZei_tCZ9Q

https://www.youtube.com/watch?v=uxQFPxbJ8So

Dear Dr Toshio Goto,
Thank you so much for your reply.

The problem I am having is, I see the slit of the lumen, often to the left or down,

which is very tight and does not open up after pulling, twisting and water infusion.

I do not have assess to cap attachment. So probably my mucosal fixation & pull back do not give good results.
Is there any thing more I can do?
Thanks for your help.

In rectum, the amount of the water infused is very small.
The more you infuse the water, the more acute becomes the angle of colon and the more tight the slit of the lumen.
The less water, the better.
A cap attachment is easy to make for yourself.
What you do is only to cut vinil tube.

Dear Dr Toshio Goto,
Thank you for your kind explanation.

I will implement the changes you have advised.
Thanks