Effect of EPA-FFA on Polypectomy in Familial Adenomatous Polyposis

Inclusion Criteria 1. Must give written informed consent. 2. Male or female subjects, 18 to 65 years of age. 3. Known diagnosis of FAP defined as those with a pathogenic APC mutation 4. Patients have had a previous colectomy with an ileo-rectal anastomosis or an ileal pouch- anal anastomosis with a rectal remnant of ≥ 2cm. 5. Classified stage 1-3 on InSiGHT Polyposis Staging System (IPSS). 6. Subjects must show a willingness to abstain from regular use of non-steroidal anti-inflammatory medication for the trial. A cardio protective dose of aspirin (75mg-100mg) will be permitted. Exclusion Criteria: 1. Subjects with ileo-rectal anastomosis who have ≥ 20 polyps which are of \>5mm that are not amendable to removal in the rectum. 2. Subjects unwilling to have regular sigmoidoscopy examination. 3. Subjects who are due to undergo gastro-intestinal surgery related to FAP. 4. History of invasive carcinoma in the past 3 years. 5. History of pelvic radiation. 6. Known allergic reaction or intolerant to fish or fish oils. 7. Known allergic reaction to excipients of IMP and placebo. 8. Subjects who are pregnant or breast-feeding at screening. 9. Subjects taking aspirin, other than a low (75mg-100mg) cardioprotective dose on a regular basis, or other nonsteroidal anti-inflammatory drugs (NSAIDs) on a regular basis. Regular use of other NSAIDS is defined in this protocol as use greater than 14-day treatment period, and one treatment per six months for the duration of the study. 10. Subjects taking NSAIDs regularly in the 3 months prior to entry (other than low dose aspirin). 11. Subjects taking NSAID, 5-aminosalicylic acid (5-ASA or mesalamine). 12. Subjects who are taking other fish-oil supplements (e.g. cod liver oil) who are unwilling to stop them for the duration of the study. Subjects previously taking fish oil must have a washout period of 2 months prior to study enrolment. 13. Subjects who are taking warfarin or other anticoagulants. 14. Experimental agents must have been discontinued at least 8 weeks prior to screening or for a period equivalent to 5 half-lives of the agent (whichever is longer). 15. Subjects suffering from known disorders of clotting and blood coagulation. 16. Subjects who have significant abnormalities on their screening blood tests. 17. Subjects with gastrointestinal malabsorptive disease. 18. Subjects with uncontrolled hypercholesterolaemia. 19. Subjects who are deemed mentally incompetent or have a history of anorexia nervosa or bulimia. 20. Subjects who will be unavailable for the duration of the trial, deemed unable to comply with the requirements of the study protocol, likely to be noncompliant with the protocol, or who are felt to be unsuitable by the Investigator for any other reason. 21. Women of childbearing potential, defined as all women physiologically capable of becoming pregnant, unless surgically sterile, must use effective contraception (either combined oestrogen and progestogen containing hormonal contraception associated with inhibition of ovulation \[oral, intravaginal, transdermal\], progestogen only hormonal contraception associated with inhibition of ovulation \[oral, injectable, implantable\], intrauterine device \[IUD\], intrauterine hormone-releasing system \[IUS\], vasectomised partner, sexual abstinence (only considered an acceptable method of contraception when it is in line with the subjects' usual and preferred lifestyle), combination of male condom with either cap, diaphragm or sponge with spermicide \[double barrier methods\]), and willing and able to continue contraception for 1 month after the last administration of IMP. 22. Women using oral contraception must have started using it at least 2 months prior to screening. Women are not considered to be of childbearing potential if they have had 12 months of natural (spontaneous) amenorrhea with an appropriate clinical profile (e.g. age appropriate, history of vasomotor symptoms) or six months of spontaneous amenorrhea with serum FSH levels that have been confirmed to be in the "postmenopausal range". Or have had a surgical bilateral oophorectomy (with or without hysterectomy) or bilateral tubal ligation at least six weeks before the screening visit. In case of oophorectomy alone, the reproductive status of the woman should have been confirmed by follow up hormone level assessment.