The intestines include a mucousal lining that naturally sectretes mucous as part of its lubrication mechanism. This mucous should be clear, odorless and thin...not much thicker than water. Many things can change the consistency of this mucous...foods (dairy is a big one)...medications ...catching a bug...pathogenic organisims...toxin exposures....etc....making it thicker, darker and malodorous.
Sounds like what you experienced is perfectly normal...not to worry. ; )