Is ghusl required, or is wudu and changing undergarments sufficient, when there is transparent, sweat-like wetness, without color or odor, sometimes accompanied by lower abdominal pain, knowing that this occurs daily and is not a wet dream?

If one wakes up and finds wetness but does not know if it is mani (seminal fluid) or something else: If he is certain it is mani, then ghusl (definition) (ritual bath) is obligatory. If he is certain it is madhiy (pre-seminal fluid), then ghusl is not obligatory; rather, it is necessary to cleanse the area and wash the penis. However, if he is in doubt and both possibilities exist, then it is more cautious to perform ghusl to avoid disagreement.