So, I’m writing a novel, and one of the central characters in my story (but one who isn’t my protagonist) suffers from ulcerative colitis, an inflammatory bowel disease. I explain what the disease is, its effects on one’s lifestyle, the challenges my character faces (incontinence, diarrhea, arthritis, etc.), and I even mention once that he found blood in his stool. Is this “too much” for the average reader’s taste? Mind you, my intended audience is the legal thriller crowd, and the character in question is a district attorney who’s sidetracked in his goal of prosecuting thugs because of his health. Do you suspect the average legal thriller fan (think: people who read John Grisham) would be put off by this problem? Would a more common disease (cancer maybe?) seem less icky?
I do confess, I’d feel a bit “ick” about it. But if it makes sense in the story, contributes to the characterization, and is handled at least somewhat deftly, I’d get through it.
Thank you for your candor. May I ask what kind of fiction you enjoy most?
Sure. I know enough people in real life with inflammatory bowel disease.
Besides, that topic has been successful in other media. Remember the Beatles big hit song, The girl with colitis goes by?
What?
You might have a look at the Enderby novels by Anthony Burrgess, for an example of an afflicted character.
If someone’s willing to read my opening chapter (where I describe the character’s condition), I’ll email it to you. It’s roughly 7,700 words, and it sets the tone for the rest of the book, including how my DA’s health relates to the story. Also, if anyone’s willing to critique-- however briefly-- the entire novel (76,000 words), I’ll gladly send you a free copy from my Amazon Kindle Store. Just let me know, and I appreciate the feedback, regardless if you read my work or comment on the OP.
It would have made Crime and Punishment more interesting.
I’ll bet doctors know all kinds of inside jokes. 
Easy for you to say, but I was just married, up to my eyeballs in debt, and exorcising the demons of a nasty gambling addiction. WHAT DO YOU PEOPLE WANT FROM ME?
Sure, send me the opening chapter, lynnbodoniathotmaildotcom. I happen to have IBS, and while I do read legal thrillers, I don’t read John Grisham unless I happen to find one of the books on the clearance wall at Half Price Books for $1 or $2. I do like legal thrillers, I just think that Grisham is repetitive.
“P” is for Pain In The Ass.
I’m not sure ‘put off’ is the right phrase, but – well, look, if it’s light comedy I can pretty much skip over those sections. Autobiography? Fine, sure, I can flip ahead to a part that interests me. But here, I’m all in: you might be doing a fair-play mystery, and you might be bastard enough to innocuously relay that one key piece of evidence when our hero is graphically enduring toilet time. Which means I have to linger over every word.
So I’m not saying I’d stop reading, but it’d bug me twice as much as usual.
My favorite genre is “urban fantasy,” but I’m fond of sci-fi, thrillers, light mysteries, and the occasional classic. (Project Gutenberg is GREAT!)
I’m a total wimp, and cannot handle horror.
Dean Koontz wrote a few “Christopher Snow” books whose protagonist could not be exposed to sunlight or artificial light. They were quite successful. In another series of books (the Odd Thomas series, I think) he talks about an author that accepted a bet regarding creating a protagonist with a disease, so the character created a series of books with a woman sleuth that had bulimia (Ozzie Boone did it, IIRC).
Always wondered if Koontz was referring to the Chris Snow books with that reference.
EDIT: If you bring it up, it should have an effect on the novel further down the line, like he/she gets too sick to do something important/help someone at a vital time, etc.
I wouldn’t be too bothered. It’s better than some very overused problems that writers sometimes seem to add to their characters. If you use this bowel problem right in the novel, I probably wouldn’t mind at all.
And don’t forget the popular Eagles song with the line “warm smell of colitis / rising up through the air”. Fairly revolting if you think about it.
Have you seen Dennis Potter’s The Singing Detective, which features:
I’m definitely going to steal that one!
I rarely read for enjoyment anything other than the bowel problems of the characters. Have I ever told you about the four instances of constipation in the Bible? Cain wasn’t Abel. Moses took two tablets. Solomon sat on the throne for 40 years and Balaam had trouble with his ass.
I don’t usually read legal thrillers, but it wouldn’t bother me if a character had ulcerative colitis. If his condition is organic to the story, helps explain why he behaves the way he does, and so on, it could be good. My only concern is that if it’s not handled properly, it may feel like a diagnosis tacked on by the author in a desperate attempt to make the character more interesting. Sometimes when reading a bad book or watching a bad movie, I can almost imagine the writer saying to himself something like this: “Gee, I’m pretty happy with the story but them main character is kind of a drip. Roll a die. If it comes up 1 or 2, give him a shady criminal past; 3 or 4, a tragically lost love; 5 or 6, a dread disease. Aha! Disease it is. Now close your eyes, open a medical dictionary at random, and point.”
In a doctor’s office, I once overheard a patient’s wife telling the receptionist that her husband had “all sorts of colitis.”
I would not read it. Or rather, I would not read it if the author felt the need to tell me they had a bowel problem. What’s wrong with the character being open about the fact he has an illness and refusing to go into more detail than that?
Have you ever really paid attention to the first few lines of The Girl From Ipanema, it ain’t about a pretty girl.
Tall and tan and young and lovely, the girl from Ipanema goes walking
And when she passes, each one she passes goes - ah