[1] Univ Sains Malaysia, Biostat & Res Methodol Unit, Sch Med Sci, Kubang Kerian, Kelantan, Malaysia
[2] Univ Sains Malaysia, Exercise & Sport Sci Programme, Sch Hlth Sci, Kubang Kerian, Kelantan, Malaysia
[3] Univ Sains Malaysia, Dept Med, Sch Med Sci, Kubang Kerian, Kelantan, Malaysia
[4] Univ Sains Malaysia, Hosp USM, GI Funct & Motil Unit, Kubang Kerian, Kelantan, Malaysia
[5] Univ Sains Malaysia, Sch Distance Educ, George Town, Malaysia
[6] Brunel Univ, Dept Life Sci, London, England