Hi Silke, There doesn’t need to be a contradiction between those two views of the Large Intestine. I find it useful to look at the direction of energy rather than its function.
The direction of Large Intestine Qi is OUTWARD. So it can help push things out that are toxic but it can also push back against outside pressure so that you stand your ground and assert your space.
Different personalities will find different things difficult. You might find that letting go of things and pushing them away is difficult, another person may find it difficult to resist outside pressure. In both cases, the Large Intestine can give help in doing them.
Just see the Large Intestine as helping OUTWARD directed actions and as a continuation of the EXPANDING energy of the Lung.