John F. Kennedy had symptoms that may have been IBD, autoimmune disorder, two diagnosed endocrine disorders, and myriad other health problems that likely made him, despite his youth during the years of his Presidency, the most unhealthy sitting US President ever. This from his wiki:
"In 2002 Robert Dallek wrote an extensive history of Kennedy's health. Dallek was able to consult a collection of Kennedy-associated papers from the years 1955-1963 including x-rays and prescription records from the files of White House physician Dr. Janet Travell. According to Travell's records, during his Presidential years Kennedy suffered from: high fevers, stomach, colon, and prostate issues, abscesses, high cholesterol, and adrenal problems. Travell kept a "Medicine Administration Record," cataloguing Kennedy's medications: "injected and ingested corticosteroids for his adrenal insufficiency; procaine shots and ultrasound treatments and hot packs for his back; Lomotil, Metamucil, paregoric, phenobarbital, testosterone, and trasentine to control his diarrhea, abdominal discomfort, and weight loss; penicillin and other antibiotics for his urinary-tract infections and an abscess; and Tuinal to help him sleep."[10]
Years after Kennedy's death, it was revealed that in September 1947, while Kennedy was 30 and in his first term in Congress, he was diagnosed by Sir Daniel Davis at The London Clinic with Addison's disease, a rare endocrine disorder. In 1966 Dr. Travell revealed that Kennedy also had hypothyroidism. The presence of two endocrine diseases raises the possibility that Kennedy had autoimmune polyendocrine syndrome type 2 (APS 2).[259]
Kennedy also suffered from chronic and severe back pain, for which he had surgery and was written up in the American Medical Association's Archives of Surgery. Kennedy's condition may have had diplomatic repercussions, as he appears to have been taking a combination of drugs to treat severe back pain during the 1961 Vienna Summit with Soviet Premier Nikita Khrushchev. The combination included hormones, animal organ cells, steroids, vitamins, enzymes, and amphetamines, and possible potential side effects included hyperactivity, hypertension, impaired judgment, nervousness, and mood swings.Kennedy at one time was regularly seen by no fewer than three doctors, one of whom, Max Jacobson, was unknown to the other two, as his mode of treatment was controversial[261] and used for the most severe bouts of back pain.
There were disagreements among his doctors, into late 1961, over the proper balance of medication and exercise, with the president preferring the former as he was short on time and desired immediate relief. During that timeframe the president's physician, George Burkley, did set up some gym equipment in the White House basement where Kennedy did stretching exercises for his back three times a week. Details of these and other medical problems were not publicly disclosed during Kennedy's lifetime.[264]"
http://en.wikipedia.org/wiki/John_F._Kennedy
What's interesting is that the Army disqualified Kennedy because of his back problems but the Navy enlisted him and let him captain PT-109, and his service during World War II was recognized with various medals after PT-109 was rammed and sunk and he saved some of his men. I wonder whether a peacetime US Navy would have enlisted him for active service with all the health issues he had.
http://en.wikipedia.org/wiki/John_F._Kennedy