You should offer congregational Salah even if you have a rumbling noise in your stomach. Taharah (ritual purification) is not invalidated
by mere audible rumbling as long as no gases are emitted. However, if you pass gas, your Wudu' is invalidated, and you should perform Taharah to offer Salah and hold the Mus-haf. It is a Sunnah (action following the teachings of the Prophet) to perform Wudu' before sleep. (Part No. 4; Page No. 107) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.