"It seemed like the standard sort of bug issue when I get back from India," he told ABCNews.com at the time. "But it continued and got different, to the point where I was doubled up on the floor, and I was having trouble eating."
Because of his age, doctors never suspected cancer and looked at every other possibility, "including the plague," Guha said.
A battery of tests were negative, but eventually a colonoscopy revealed a 6 cm.-wide tumor in the sigmoid colon.
When he saw a report that suggested it was malignant, Guha said, "I was in denial. I thought surely there was another explanation."
MRIs and surgery revealed that the cancer had proliferated into his entire abdominal cavity: a stage-4 diagnosis. "It was pretty dire," he said.
Guha had a colostomy, conventional chemotherapy, the removal of his gall bladder and a heated chemo bath of the lining of his stomach, as the medical bills mounted.
By the time Guha had exhausted his insurance benefits, he had about $118,000 in medical bills.
For a time, he dedicated himself to fundraising for more support for cancer patients and their families, especially Arizona's undocumented, who have no insurance.
"I could never get through life like that or be a productive member of society," he said then. "I have always dedicated my life to doing something useful."