It was narrated from Abu Umamah that:The Messenger of Allah forbade a man to perform prayer when he was suppressing (the urge to urinate or defecate)
Hadith No. 617
Sunan Ibn Majah
Gradings:
Al-Albani:
Daif
Muhammad Fouad Abd al-Baqi:
Sahih
Shuaib Al Arnaut:
Sahih Lighairihi
Zubair Ali Zai:
Sahih