And Mula-Bandha also helps to awaken Kundalini, as the Mula-Bandha stimulates the Muladhara chakra.

Though some of our Yoga Gurus just tell to do some Kriyas and never tell the science behind them. But this video tells lot of things about Mula-Bandha. They use some technical terms but in my plain words: the end part of intestine stores emotions, if emotions are sick that part is going to suffer as emotions are stored in energy it manifests something, maybe some disease. Another thing is, the end part of intestine which touches the anus, that place is also for Muladhara Chakra — when the Aswani Mudra (contraction and expansion of anus, as a horse does) is done few times, let’s say 20-30 times and after it the Mula Bandha (contraction of anus) is used, let’s say for a minute or two. It helps releasing tension and haemorrhoids problem … along with stimulating Kundalini.

Update:

Also listen “HH Mahamandaleshwar Paramhans Sri Swami Maheshwaranandaji” on Jalandhar Bandha, if you are suffering from Thyroid problem, it may be a cure for you. And also listen on Uddyan Bandha. The three of them altogether Mula-Bandha + Jalandhar Bandha + Uddyan Banda — make Maha-Bandha.