Table 1. Study characteristics.
| Study | Year | Country | Design | CCE type | N | Laxative | Booster | Prokinetic(s) |
| Schoofs 11 | 2006 | Belgium | OBS | CCE1 | 41 | PEG | NaP | DOM |
| van Gossum 12 | 2009 | France | OBS | CCE1 | 332 | PEG | NaP | DOM |
| Eliakim 13 | 2009 | Israel | OBS | CCE2 | 98 | PEG | NaP | DOM |
| Gay 14 | 2010 | France | OBS | CCE1 | 128 | PEG | NaP | DOM |
| Spada 15 | 2011 | Italy | OBS | CCE2 | 117 | PEG | NaP | DOM |
| Herrerìas-Gutiérrez 16 | 2011 | Spain | OBS | CCE1 | 144 | PEG | NaP | DOM |
| Spada 17 | 2011 | Italy | OBS | CCE2 | 47 | PEG | NaP | DOM |
| Rondonotti 18 | 2014 | Italy | OBS | CCE2 | 50 | PEGAA | NaP | MET |
| Hagel 19 | 2014 | Germany | OBS | CCE2 | 24 | PEG | NaP | NA |
| Triantafyllou 20 | 2014 | Greece | OBS | CCE1 | 50 | PEG | NaP | DOM |
| Saito 21 | 2015 | Japan | OBS | CCE2 | 72 | PEG | PEG + MgCit + MOS | MET/MOS |
| Rex 22 | 2015 | USA, France, China, Spain, Israel | OBS | CCE2 | 792 | PEG | Suprep | MET |
| Spada 23 | 2015 | Italy | OBS | CCE2 | 100 | PEG | NaP + GG | DOM |
| Togashi 24 | 2015 | Japan | OBS | CCE2 | 29 | PEGAA | PEG + GG + MOS | DOM |
| Boal Carvalho 25 | 2015 | Portugal | OBS | CCE2 | 12 | PEG | NaP | DOM |
| Romero-Vazquez 26 | 2016 | Spain | OBS | CCE1 /CCE2 | 165 | PEG | NaP | MET |
| Ota 27 | 2017 | Japan | OBS | CCE2 | 20 | PEG | PEG + MgCit | NA |
| Zhou 28 | 2017 | China | OBS | CCE2 | 31 | PEG | PEG + MOS | NA |
| Nogales 29 | 2017 | Spain | OBS | CCE2 | 96 | PEG | NaP | MET |
| Igawa 30 | 2017 | Japan | OBS | CCE2 | 30 | PEG | PEG + MgCit + MOS | MET |
| Sato 31 | 2017 | Japan | OBS | CCE2 | 70 | PEG + MgCit | PEG + MgCit + MOS | MET |
| Pioche 32 | 2018 | France | OBS | CCE2 | 20 | PEG | NaP | DOM |
| Takano 33 | 2018 | Japan | OBS | CCE2 | 30 | MgCit + Sennoside | PEGAA + MgCit | MOS |
| Kobaek-Larsen 34 | 2018 | Denmark | OBS | CCE2 | 253 | PEGAA | PEGAA | DOM |
| Okabayashi 35 | 2018 | Japan | OBS | CCE2 | 39 | PEG | PEG + CO | MET |
| Eliakim 36 | 2018 | Israel, Italy, Spain | OBS | PCCE | 41 | PEG | Suprep | MET |
| Parodi 37 | 2018 | Italy, France | OBS | CCE2 | 177 | PEG | NaP | DOM |
| Baltes 38 | 2018 | Germany | OBS | CCE2 | 36 | PEGAA | PEGAA + NaP | DOM |
| Voska 39 | 2019 | Czech Republic | OBS | CCE2 | 236 | PEG | NaP | MET |
| Yamada 40 | 2019 | Japan | OBS | CCE2 | 53 | PEG | PEG + CO + NaP + MOS | NA |
| González-Suárez 41 | 2020 | Spain | OBS | CCE2 | 147 | PEGAA | PEGAA + GG | MET |
| Otani 42 | 2020 | Japan | OBS | CCE2 | 60 | PEG | PEG + MgCit + MOS | NA |
| Pecere 43 | 2020 | Italy | OBS | CCE2 | 222 | PEG | NaP + GG | DOM |
| Utano 44 | 2020 | Japan | OBS | CCE2 | 27 | PEGAA + Sodium picosulfate | MgCit + GG | DOM |
| Eliakim 45 a | 2006 | Israel | RCT | CCE1 | 44 | PEG | NaP | Tegaserod |
| Eliakim b | 2006 | RCT | CCE1 | 46 | PEG | NaP | Tegaserod | |
| Spada 46 a | 2011 | Italy | RCT | CCE2 | 20 | PEG | PEG | DOM |
| Spada b | RCT | CCE2 | 20 | PEG | NaP | DOM | ||
| Hartmann 47 a | 2012 | Germany | RCT | CCE2 | 26 | PEGAA | PEGAA | DOM |
| Hartmann b | RCT | CCE2 | 24 | PEGAA | PEGAA | DOM | ||
| Kakugawa 48 a | 2012 | Japan | RCT | CCE1 | 33 | PEG | MgCit | MOS |
| Kakugawa b | RCT | CCE1 | 31 | PEG | MgCit | MOS | ||
| Argüelles-Arias 49 a | 2014 | Spain | RCT | CCE2 | 28 | PEGAA | NaP | DOM |
| Argüelles-Arias b | RCT | CCE2 | 30 | PEG | NaP | DOM | ||
| Ramos50 a | 2014 | Spain | RCT | CCE1 | 20 | PEG | NaP | DOM |
| Ramos b | RCT | CCE1 | 20 | PEG | NaP | DOM | ||
| Brechmann51 a | 2016 | Germany | RCT | CCE1 | 20 | PEGAA | PEGAA | ERY |
| Brechmann b | RCT | CCE1 | 6 | PEGAA | PEGAA | ERY | ||
| Brechmann c | RCT | CCE1 | 12 | PEGAA | PEGAA | ERY | ||
| Brechmann d | RCT | CCE1 | 12 | PEGAA | PEGAA + senna tea | ERY | ||
| Kastenberg 52 a | 2017 | USA, Cyprus | RCT | CCE2 | 55 | PEG | Suprep + GG | MET/ERY |
| Kastenberg b | RCT | CCE2 | 52 | PEG | Suprep | MET/ERY | ||
| Alvarez-Urturi 53 a | 2017 | Spain | RCT | CCE1 | 27 | PEGAA | PEGAA | MET |
| Alvarez-Urturi b | RCT | CCE1 | 24 | PEGAA | NaP | MET | ||
| Buijs 54 a | 2018 | Denmark | RCT | CCE2 | 57 | PEGAA | PEGAA + chewing gum | DOM |
| Buijs b | RCT | CCE2 | 48 | PEGAA | PEGAA + coffee | DOM | ||
| Buijs c | RCT | CCE2 | 60 | PEGAA | PEGAA | DOM | ||
| Kroijer 55 a | 2018 | Denmark | RCT | CCE2 | 60 | PEGAA | PEGAA | DOM |
| Kroijer b | RCT | CCE2 | 60 | PEGAA | Sulfate based solution | DOM | ||
| Kroijer c | RCT | CCE2 | 60 | PEGAA | PEGAA + GG | DOM | ||
| Ohmiya 56 a | 2018 | Japan | RCT | CCE2 | 152 | PEGAA | PEGAA + CO | MET or MgCit + MOS |
| Ohmiya b | RCT | CCE2 | 167 | PEGAA | PEGAA | MOS |
CCE, colon capsule endoscopy; CO, castor oil; DOM, domperidone; ERY, erythromycin; GG, Gastrografin; MET, metoclopramide; MgCit, magnesium citrate; MOS, mosapride; NA, not available; NaP, sodium phosphate; OBS, observational study; PEG, polyethylene glycol; PEGAA, polyethylene glycol and ascorbic acid; RCT, randomized controlled trial.