All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
Speech in the bathroom either involves remembrance of Allah or not. If it does involve remembering Allah, scholars are of different views on it. Some hold the opinion that it is dislikable and others are of the opinion that it is prohibited. The point of view that we in Islamweb hold is that it is prohibited since it is in clear contradiction with the due respect and exaltation we must show towards Allah Almighty. If the speech does not involve remembrance of Allah then it is dislikable. This is according to the Prophet's Hadith: "No two men should go out to answer the call of nature with their private parts (or other parts of the body which should not to be seen by others) exposed and talking to each other, for Allah abhors that." [Narrated by Abu Dawood] The place of answering the call of nature (lavatory) is the favorite milieu of the devils, as evidenced by the Hadith narrated in the Sahihain, in which Anas reports that whenever the Prophet enters the lavatory he would say: "O Allah! I seek refuge with You from the male and female jinn." Commenting on this Hadith, Ibn Hajar said in "Al-Fath": "Does this formula of remembrance concern the places especially prepared for this purpose (answering the call of nature) being haunted by devils, as mentioned in the Hadith narrated by Zaid Ibn Arqam in the Sunan, or does it also include passing urine, for example, in a bowel in a corner of the house? The second of these two is the most correct." Allah knows best.