Question:  After finishing the qada-e-hajat (call of nature) if one does not have( khuluq) or toilet tissue, would it suffice to use water only?

Answer: After relieving oneself from the toilet using khuluq or toilet tissue is sunnah. If however, anyone does not have or find khuluq or toilet tissue at that instance it will be sufficient to use water provided that the water is used thoroughly in the private area. Moreover, after urinating it would be wise not to use water straight away rather give some time to completely stop the last drop of urine.   

References: [1] Surah At-Tawbah V:108 [2] Darse Tirmidhi vol-1, pg-279 hadith-19 [3] Mustadrak Hakim, vol-1 pg-155 [4] Musannaf Ibn Abi Shaybah:1634 [5] Ahsanul fatwa, vol-2, pg-204