Adenomatous Polyp

In 2001, I had fistulectomy,

In 2002 as I had mucoidal discharge, I was suggested Barium Enema & Colonoscopy, in Barium Enema the impression was as follows:
1) Loss of Haustral Pattern in sigmoid and distal descending colon.
2) Normal variation or non-specific colitis.

During colonoscopy the following findings are made:
Polypoid Lesion at 10cms from rectum

The pathological report said:

Microscopic Description:
Multiple sections studied show a polyp normal to hyper plastic colonic epithelium blending imperceptibly with areas of epithelium showing blending imperceptibly by mucus depletion, nuclear pseudo stratification, nuclear enlargement and hyper chromasia with occasional nucleolar prominence. Mitoses is occasional. Stroma appears fibro collagenous with non specific inflammation.

Impression:
Adenomatous polyp with mild atypia; colonoscopic biopsy from colonic polyp.

In 2010, during PR a Polyp felt about 4 or 5 cms from end verge.
After that I was advised another clonoscopy during which the following findings were made:

Scope passed upto the ascending colon. Polyp found at the rectum was removed using a snare. Rest of colon normal.

In colonoscopy,  the pathological report says:

Impression:
Adenomatous polyp with moderate atypia; colonoscopic biopsy from colonic polyp.

Hence, I was suggested to carryout colonoscopy a year after (2011) during which the following findings were made:

Scope passed upto 150 cms. Polyp noted at 8 to 10 cms. Snaring (?) polypectomy done.

The pathological results are as follows
Microscopic description:
Sections show colonic mucosa showing adenomatous hyperplasia with tubulo-villous structures showing mild to moderate dysplasia. Mild mixed inflammatory cell infiltrate seen. Scattered mitosis is seen.

Impression:
Suggestive of Adenomatous Polyp with moderate dysplasia; Colonoscopic biopsy from rectum.

With the above details the need following doubts to be clarified by anyone expert:

1) Does the loss of Haustral Pattern in sigmoid and distal descending colon will have any ill effect for me?
2) Reccurrence of Polyp and change from Mild atypia to Moderate atypia and now to moderate dysplasia is a sign of of worst is in the store?
3) When am i suggested to have next colonoscopy?
4) What are the precautions I should take with respect to diet? ( I am presently around 100 Kg in weight)