Inclusion Criteria:

Ulcerative Colitis Patient Group (Group 1):

- Aged 18 - 80

- Male or female

- Diagnosed with ulcerative colitis

- Attending gastroenterology clinic for routine colonoscopy check-up

- Willing to increase dietary intake of fish for six months

- Willing to undergo a flexible sigmoidoscopy examination

Polyps/Resection Group (Group 2):

- Aged 18 - 80

- Male or female

- A history of polyps in the colon

- Attending gastroenterology clinic for routine colonoscopy check-up

- Willing to increase dietary intake of fish for six months

- Willing to undergo a flexible sigmoidoscopy examination

Control Group (Group 3):

- Aged 18 - 80

- Male or female

- Booked for a colonoscopy examination for the investigation of iron deficiency anaemia
of unknown cause (no evidence of macroscopic disease found during examination)

- Willing to increase dietary intake of fish for six months

- Willing to undergo a flexible sigmoidoscopy examination

Exclusion Criteria:

Ulcerative Colitis Patient Group (Group 1) and Polyps/Resection Group (Group 2):

- Allergic to fish

- Receiving anticoagulant therapy

- Diabetics

- Pregnant or breast-feeding

- Organ transplant recipients receiving immunosuppression therapy

- Prosthetic heart valve

- Allergic to pethidine

- Previous diagnosis of bacterial endocarditis

Control Group (Group 3):

Same as Groups 1 and 2 plus:

- Received a diagnosis of colorectal cancer following initial investigative colonoscopy
(volunteer will be withdrawn from the study when diagnosed as requiring treatment)

- Received a diagnosis of coeliac disease following initial investigative colonoscopy
(volunteer will be withdrawn from the study when diagnosed as requiring a modified
diet)