Norton, C; Emmanuel, A; Stevens, N; Scott, SM; Grossi, U; Bannister, S; Eldridge, S; ... Knowles, CH; + view all Norton, C; Emmanuel, A; Stevens, N; Scott, SM; Grossi, U; Bannister, S; Eldridge, S; Mason, JM; Knowles, CH; - view fewer (2017) Habit training versus habit training with direct visual biofeedback in adults with chronic constipation: study protocol for a randomised controlled trial. Trials , 18 , Article 139. 10.1186/s13063-017-1880-0.