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Dr Chok Aik Yong

MEDICAL DIRECTOR OF
AELIUS SURGICAL CENTRE

Colorectal Surgeon and General Surgeon
MBBS, MRCS (UK), MMed (Surg), FRCS (UK)

As Medical Director of Aelius Surgical Centre in Mount Elizabeth Hospital (Orchard) and Parkway East Medical Centre, Dr Chok Aik Yong provides comprehensive gastrointestinal care for our patients.

Languages & Dialects:

English, Mandarin, Bahasa Melayu, Hokkien, Cantonese

Experience

Track Record

Dr Chok has years of experience in robotic colorectal surgery, having performed more than 500 major operations for colorectal cancers, including complex cases involving adjacent organs, and more than 10,000 endoscopy procedures. 

Public Service Background

Prior to private practice, he was in public service for over 15 years, serving as a consultant in the Department of General Surgery at Singapore General Hospital.

He was a member of the multi-disciplinary IBD team, operating on various Crohn’s disease and ulcerative colitis cases. He was also a member of the SGH pelvic exenteration team, performing numerous multi-organ surgeries for advanced colorectal cancers. Dr Chok was also part of the colorectal genetics and hereditary disorders service at SGH.

In 2019 he was awarded the Health Manpower Development Plan (HMDP) Award to undertake advanced colorectal training at the Royal Marsden Hospital, London, one of the world’s leading cancer centres, where he focused on the surgical management of advanced colorectal cancer and inflammatory bowel disease.

Professional Qualifications and Credentials

Credentials:

  • MBBS, Bachelor of Medicine and Bachelor of Surgery, National University of Singapore
  • MMed (Surgery), Master of Medicine, National University of Singapore
  • MRCS (UK), Member of the Royal College of Surgeons
  • FRCS (Edinburgh), Fellow of the Royal College of Surgeons of Edinburgh, 2016
  • Registered Specialist (General Surgery), accredited by the Singapore Medical Council (SMC public register)

 

Current Appointments:

  • Medical Director and resident Colorectal Surgeon, Aelius Surgical Centre
  • Admitting and operating privileges: Mount Elizabeth Hospital (Orchard) and Parkway East Hospital
  • Active member, PelvEx Collaborative (international pelvic exenteration research group)
  • Appointed reviewer, British Journal of Surgery
  • Appointed reviewer, Annals, Academy of Medicine Singapore

Expertise

Dr Chok’s expertise lies in managing colorectal diseases, particularly advanced colorectal cancer and inflammatory bowel disease. He also treats surgical conditions such as hernia, haemorrhoids, anal fistula and bowel disorders. Dr Chok has a special interest in minimally invasive colorectal surgery and procedures like these:

  • Robotic Colorectal Cancer Surgery
  • Laparoscopic Surgery
  • Gastroscopy
  • Colonoscopy
  • Advanced Endoscopy

Scientific Publications

Dr Chok has authored and co-authored 48 peer-reviewed scientific publications indexed on PubMed in international medical journals. See his his verified author profiles on ORCID, Scopus and PubMed.

Full list of Dr Chok's publications
  1. Zhao Y, Goh BKP, Chok AY, Koh YX. Survival Outcomes in Nonmetastatic pT4 Pancreatic Ductal Adenocarcinoma: A SEER Database Analysis Comparing Neoadjuvant Therapy and Upfront Surgery with Propensity Score Matching. Asian Pac J Cancer Prev. 2025 Mar 1;26(3):847-859. Free full text (PMC)
  2. Zhu G, Rahman CR, Getty V, Odinokov D, Baruah P, Carrié H, Lim AJ, Guo YA, Poh ZW, Sim NL, Abdelmoneim A, Cai Y, Lakshmanan LN, Ho D, Thangaraju S, Poon P, Lau YT, Gan A, Ng S, Koo SL, Chong DQ, Tay B, Tan TJ, Yap YS, Chok AY, Ng MCH, Tan P, Tan D, Wong L, Wong PM, Tan IB, Skanderup AJ. A deep-learning model for quantifying circulating tumour DNA from the density distribution of DNA-fragment lengths. Nat Biomed Eng. 2025 Mar;9(3):307-319. PubMed
  3. Neo SY, Shuen TWH, Khare S, Chong J, Lau M, Shirgaonkar N, Chua L, Zhao J, Lee K, Tan C, Ba R, Lim J, Chua J, Cheong HS, Chai HM, Chan CY, Chung AYF, Cheow PC, Jeyaraj PR, Teo JY, Koh YX, Chok AY, Chow PKH, Goh B, Wan WK, Leow WQ, Loh TJZ, Tang PY, Karunanithi J, Ngo NT, Lim TKH, Xu S, Dasgupta R, Toh HC, Lam KP. Atypical memory B cells acquire Breg phenotypes in hepatocellular carcinoma. JCI Insight. 2025 Feb 25;10(7):e187025. Free full text (PMC)
  4. Ng YY, Tan KY, Zhao Y, Seow-En I, Chok AY, Chuang J, Loy MS, Tan EK. Efficacy of Traditional Acupuncture Compared to Biofeedback Therapy in Fecal Incontinence: A Randomized Controlled Trial. Dis Colon Rectum. 2024 Oct 1;67(10):1313-1321. PubMed
  5. Wee IJY, Seow-En I, Chok AY, Sim E, Koo CH, Lin W, Meihuan C, Tan EK. Postoperative outcomes after prehabilitation for colorectal cancer patients undergoing surgery: a systematic review and meta-analysis of randomized and nonrandomized studies. Ann Coloproctol. 2024 Jun;40(3):191-199. Free full text (PMC)
  6. Tan SJJ, Tan EK, Ng YYR, Sultana R, Allen JC, Seow-En I, Mathew R, Chok AY. Venous thromboembolism among Asian populations with localized colorectal cancer undergoing curative resection: is pharmacological thromboprophylaxis required? A systematic review and meta-analysis. Ann Coloproctol. 2024 Jun;40(3):200-209. Free full text (PMC)
  7. Lin W, Chok AY, Seow-En I, Tan EK. Stenting as bridge to surgery versus upfront emergency resection for non-metastatic left sided obstructing colorectal cancer: risk of peritoneal recurrence and long-term outcomes. Surg Endosc. 2024 May;38(5):2632-2640. PubMed
  8. Seow-En I, Koh YX, Zhao Y, Ang BH, Tan IE, Chok AY, Tan EJKW, Au MKH. Predictive modeling algorithms for liver metastasis in colorectal cancer: A systematic review of the current literature. Ann Hepatobiliary Pancreat Surg. 2024 Feb 29;28(1):14-24. Free full text (PMC)
  9. Ng YY, Seow-En I, Chok AY, Lee TS, Palanisamy P, Tan EK. Surgical and short-term oncological safety of total neoadjuvant therapy in high-risk locally advanced rectal cancer. ANZ J Surg. 2024 Feb;94(1-2):175-180. PubMed
  10. Lin W, Yoon S, Zhao Y, Seow-En I, Chok AY, Tan EKW. Patient-reported unmet supportive care needs in long-term colorectal cancer survivors after curative treatment in an Asian population. Asian J Surg. 2024 Jan;47(1):256-262. PubMed
  11. Lin W, Wee IJY, Seow-En I, Chok AY, Tan EK. Survival outcomes of salvage surgery in the watch-and-wait approach for rectal cancer with clinical complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis. Ann Coloproctol. 2023 Dec;39(6):447-456. Free full text (PMC)
  12. Tan EJKW, Chen HLR, Chok AY, Tan IE, Zhao Y, Lee RS, Ang KA, Au MKH, Ong HS, Ho HSS, Poopalalingam R, Tan HK, Kwek KYC. A reduction in hospital length of stay reduces costs for colorectal surgery: an economic evaluation of the National Surgical Quality Improvement Program in Singapore. Int J Colorectal Dis. 2023 Oct 26;38(1):257. PubMed
  13. Chok AY, Zhao Y, Chen HLR, Tan IE, Chew DHW, Zhao Y, Au MKH, Tan EJKW. Elderly patients over 80 years undergoing colorectal cancer resection: Development and validation of a predictive nomogram for survival. World J Gastrointest Surg. 2023 May 27;15(5):892-905. Free full text (PMC)
  14. Chok AY, Tan IE, Zhao Y, Chee MYM, Chen HLR, Ang KA, Au MKH, Tan EJKW. Clinical outcomes and cost comparison of laparoscopic versus open surgery in elderly colorectal cancer patients over 80 years. Int J Colorectal Dis. 2023 Jun 6;38(1):160. PubMed
  15. Koo CH, Chok AY, Wee IJY, Seow-En I, Zhao Y, Tan EJKW. Effect of preoperative oral antibiotics and mechanical bowel preparation on the prevention of surgical site infection in elective colorectal surgery, and does oral antibiotic regime matter? a bayesian network meta-analysis. Int J Colorectal Dis. 2023 May 31;38(1):151. PubMed
  16. Tan IE, Chok AY, Zhao Y, Chen Y, Koo CH, Aw J, Soh MHT, Foo CH, Ang KA, Tan EJKW, Tan AHC, Au MKH. Acute hospital-community hospital care bundle for elderly orthopedic surgery patients: A propensity score-matched economic analysis. World J Orthop. 2023 Apr 18;14(4):231-239. Free full text (PMC)
  17. Chen HLR, Seow-En I, Chok AY, Ngo NT, Cheng TL, Tan KE. The role of magnetic resonance tumour regression grade in the prediction of regression and survival of rectal adenocarcinoma after long-course chemoradiotherapy: a cohort study. Ann Med Surg (Lond). 2023 Apr 3;85(4):842-848. Free full text (PMC)
  18. Lam KK, Low YS, Lo M, Wong M, Leong Tang C, Tan E, Chok AY, Seow-En I, Wong SH, Cheah PY. KRAS-specific antibody binds to KRAS protein inside colorectal adenocarcinoma cells and inhibits its localization to the plasma membrane. Front Oncol. 2023 Mar 27;13:1036871. Free full text (PMC)
  19. Chok AY, Zhao Y, Tan IE, Au MKH, Tan EJKW. Cost-effectiveness comparison of minimally invasive, robotic and open approaches in colorectal surgery: a systematic review and bayesian network meta-analysis of randomized clinical trials. Int J Colorectal Dis. 2023 Mar 29;38(1):86. PubMed
  20. Chok AY, Zhao Y, Lim HJ, Ng YYR, Tan EJKW. Stenting as a bridge to surgery in obstructing colon cancer: Long-term recurrence pattern and competing risk of mortality. World J Gastrointest Endosc. 2023 Feb 16;15(2):64-76. Free full text (PMC)
  21. Ng WKD, Chok AY, Ng YY, Seow-En I, Tan EK. Efficacy of biofeedback therapy for faecal incontinence in an Asian population. ANZ J Surg. 2023 May;93(5):1262-1266. PubMed
  22. Han S, Chok AY, Peh DYY, Ho JZ, Tan EKW, Koo SL, Tan IB, Ong JC. The distinct clinical trajectory, metastatic sites, and immunobiology of microsatellite-instability-high cancers. Front Genet. 2022 Dec 1;13:933475. Free full text (PMC)
  23. Cheruba E, Viswanathan R, Wong PM, Womersley HJ, Han S, Tay B, Lau Y, Gan A, Poon PSY, Skanderup A, Ng SB, Chok AY, Chong DQ, Tan IB, Cheow LF. Heat selection enables highly scalable methylome profiling in cell-free DNA for noninvasive monitoring of cancer patients. Sci Adv. 2022 Sep 9;8(36):eabn4030. Free full text (PMC)
  24. Joanito I, Wirapati P, Zhao N, Nawaz Z, Yeo G, Lee F, Eng CLP, Macalinao DC, Kahraman M, Srinivasan H, Lakshmanan V, Verbandt S, Tsantoulis P, Gunn N, Venkatesh PN, Poh ZW, Nahar R, Oh HLJ, Loo JM, Chia S, Cheow LF, Cheruba E, Wong MT, Kua L, Chua C, Nguyen A, Golovan J, Gan A, Lim WJ, Guo YA, Yap CK, Tay B, Hong Y, Chong DQ, Chok AY, Park WY, Han S, Chang MH, Seow-En I, Fu C, Mathew R, Toh EL, Hong LZ, Skanderup AJ, DasGupta R, Ong CJ, Lim KH, Tan EKW, Koo SL, Leow WQ, Tejpar S, Prabhakar S, Tan IB. Single-cell and bulk transcriptome sequencing identifies two epithelial tumor cell states and refines the consensus molecular classification of colorectal cancer. Nat Genet. 2022 Jul;54(7):963-975. Free full text (PMC)
  25. Chen HLR, Chok AY, Cheng TL, Tan KE. Pouch volvulus after laparoscopic ileal pouch anal anastomosis: the Achilles heel?. ANZ J Surg. 2022 Sep;92(9):2322-2323. PubMed
  26. Seow-En I, Chok AY, Tan EK. Transanal total mesorectal excision with two stage Turnbull-Cutait pull-through for delayed low anastomotic leakage – A video vignette. Colorectal Dis. 2022 Mar;24(3):331-332. PubMed
  27. Seow-En I, Chok AY, Matchar DB, Yoon S, Chong DQ, Tan EK. Long-term quality of life, sexual health and gastrointestinal function following colorectal cancer resection in an Asian cohort. Colorectal Dis. 2021 Sep;23(9):2348-2360. PubMed
  28. Guo J, Chok AY, Lim HJ, Tay WX, Lye WK, Samarakoon LB, Tan EJ, Mathew R. Prognostic Value of Neutrophil-to-Lymphocyte Ratio in Obstructing Colorectal Cancer Treated by Endoscopic Stenting as a Bridge to Surgery. Ann Coloproctol. 2021 Jun;37(3):159-165. Free full text (PMC)
  29. Chang TP, Chok AY, Tan D, Rogers A, Rasheed S, Tekkis P, Kontovounisios C. The Emerging Role of Robotics in Pelvic Exenteration Surgery for Locally Advanced Rectal Cancer: A Narrative Review. J Clin Med. 2021 Apr 5;10(7):1518. Free full text (PMC)
  30. Carbone F, Kaur MM, Chok AY, Kontovounisios C, Ind T, Rasheed S. Endometrial stromal sarcoma arising from polypoid endometriosis: Case report and literature review. Int J Surg Case Rep. 2020;72:537-540. Free full text (PMC)
  31. Yee FZY, Chok AY, Wong TH. Emergency laparoscopic repair of an incarcerated obturator hernia, a case report. Int J Surg Case Rep. 2020;73:13-14. Free full text (PMC)
  32. Tan HL, Chok AY, Li Y, Tan WS. Systemic Amyloid Light-chain amyloidosis with colonic involvement complicated by colo-colic intussusception. ANZ J Surg. 2020 Jun;90(6):1162-1163. PubMed
  33. Chok AY, Lim HJ, Lye WK, Samarakoon LB, Guo J, Tang CL, Mathew R. Stenting as a bridge to surgery for obstructed stage IV colorectal cancers – long-term outcomes of a 10-year study. Asian J Endosc Surg. 2020 Jul;13(3):343-350. PubMed
  34. Tan DTM, Chok AY, Farah BL, Yan YY, Toh EL. Spontaneous partial regression of a microcystic jejunal mesenteric lymphangioma and a proposed management algorithm. BMJ Case Rep. 2019 Nov 24;12(11):e231037. Free full text (PMC)
  35. Chok AY, Sri Murali K, Wong HM, Leow WQ, Kalimuddin S, Wong TH. Rare case of enterocolitis. ANZ J Surg. 2019 Nov;89(11):1525. PubMed
  36. Koh YX, Lee SY, Chok AY, Chung AY. Icteric Intraductal Hepatocellular Carcinoma and Bile Duct Thrombus Masquerading as Hilar Cholangiocarcinoma. Ann Acad Med Singap. 2016 Mar;45(3):113-6. PubMed
  37. Goh BK, Chok AY, Allen JC Jr, Quek R, Teo MC, Chow PK, Chung AY, Ong HS, Wong WK. Blood neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios are independent prognostic factors for surgically resected gastrointestinal stromal tumors. Surgery. 2016 Apr;159(4):1146-56. PubMed
  38. Koh YX, Chok AY, Wong AS. Perforated duodenal diverticulum as an unusual sequelae of intestinal obstruction. ANZ J Surg. 2016 Jun;86(6):516-7. PubMed
  39. Koh YX, Zheng HL, Chok AY, Tan CS, Wyone W, Lim TK, Tan DM, Goh BK. Systematic review and meta-analysis of the spectrum and outcomes of different histologic subtypes of noninvasive and invasive intraductal papillary mucinous neoplasms. Surgery. 2015 Mar;157(3):496-509. PubMed
  40. Chok AY, Goh BK, Koh YX, Lye WK, Allen JC Jr, Quek R, Teo MC, Chow PK, Ong HS, Chung AY, Wong WK. Validation of the MSKCC Gastrointestinal Stromal Tumor Nomogram and Comparison with Other Prognostication Systems: Single-Institution Experience with 289 Patients. Ann Surg Oncol. 2015 Oct;22(11):3597-605. PubMed
  41. Aik-Yong C, Ye-Xin K, Yi NS, Hway WT. Abdominal compartment syndrome: Incidence and prognostic factors influencing survival in Singapore. Indian J Crit Care Med. 2014 Oct;18(10):648-52. Free full text (PMC)
  42. Koh YX, Chok AY, Zheng HL, Tan CS, Goh BK. A systematic review and meta-analysis of the clinicopathologic characteristics of cystic versus solid pancreatic neuroendocrine neoplasms. Surgery. 2014 Jul;156(1):83-96.e2. PubMed
  43. Chok AY, Koh YX, Ow MY, Allen JC Jr, Goh BK. A systematic review and meta-analysis comparing pancreaticoduodenectomy versus limited resection for duodenal gastrointestinal stromal tumors. Ann Surg Oncol. 2014 Oct;21(11):3429-38. PubMed
  44. Koh YX, Chok AY, Zheng HL, Tan CS, Goh BK. Systematic review and meta-analysis comparing the surgical outcomes of invasive intraductal papillary mucinous neoplasms and conventional pancreatic ductal adenocarcinoma. Ann Surg Oncol. 2014 Aug;21(8):2782-800. PubMed
  45. Chok AY, Koh YX, Lee J, Wong AS. Secondary stent-in-stent self-expanding metallic stent placement for early stent occlusion due to mucosal oedema in the gastrojejunal anastomosis after palliative subtotal gastrectomy for locally advanced gastric cancer. Singapore Med J. 2013 Dec;54(12):e240-3. PubMed
  46. Koh YX, Chok AY, Zheng HL, Tan CS, Chow PK, Wong WK, Goh BK. A systematic review and meta-analysis comparing laparoscopic versus open gastric resections for gastrointestinal stromal tumors of the stomach. Ann Surg Oncol. 2013 Oct;20(11):3549-60. PubMed
  47. Koh YX, Chiow AK, Chok AY, Lee LS, Tan SS, Ibrahim S. Recurrent pyogenic cholangitis: disease characteristics and patterns of recurrence. ISRN Surg. 2013 May 25;2013:536081. Free full text (PMC)
  48. Goh BK, Chow PK, Chok AY, Chan WH, Chung YF, Ong HS, Wong WK. Impact of the introduction of laparoscopic wedge resection as a surgical option for suspected small/medium-sized gastrointestinal stromal tumors of the stomach on perioperative and oncologic outcomes. World J Surg. 2010 Aug;34(8):1847-52. PubMed

Beyond the clinic

Dr Chok is not only passionate about providing excellent healthcare services to his patients but also about leading a healthy lifestyle. He is an avid runner and enjoys running in the bustling streets of Singapore city. He also enjoys spending quality time with his family whenever he can.

About Aelius Surgical Centre

Aelius Surgical Centre provides specialised care for gastrointestinal conditions, diseases, and cancers. 

We understand the challenges that may come with a diagnosis and aim to guide you through every step of your treatment with clarity and compassion. Our team is committed to delivering meticulous, discreet care tailored to your individual needs.

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