Physical Bad Habits That Cause Constipation

People around me doesn't seem to have this problem.. but I do since.. forever. But then again, according to this article about Constipation, the causes of constipation are:

1. not enough fiber in the diet
2. lack of physical activity (especially in the elderly)
3. medications
4. milk
5. irritable bowel syndrome
6. changes in life or routine such as pregnancy, aging, and travel
7. abuse of laxatives
8. ignoring the urge to have a bowel movement
9. dehydration
10. specific diseases or conditions, such as stroke (most common)
11. problems with the colon and rectum
12. problems with intestinal function (chronic idiopathic constipation)

Unlikely reasons: 1, 3, 4, 6, 7, 10, 11, 12
I used to eat whatever but I always include veggies in my meal so I don't think the problem is because of the lack of fiber. Huh, I didn't know milk can cause constipation but no, I don't drink milk, yogurts and curds (dadih) that often either... Changes in life or routine has nothing to do with it since it has been going on forever. Abuse of laxatives, impossible! I plain hate any kind of drugs and medicines! Specific diseases or conditions... I don't have any or none of I'm aware of. Problems with the colon and rectum... Uh, that... how do we check that? I'm pretty sure I'm clean in that area though. Same with reason number 12.

Possible reasons: 2, 5, 8, 9
Um, yeah... I rarely move at all except to take a bath, pray, sleep, eat, sitting in front of the computer... *wince* Okay, that's a really bad idea if I want to stay healthy 50 years to come. IBS is hard to diagnose online. I've never got a medical check up for that but considering I always have some type of abdominal discomfort (bloating, cramps, et cetera) and is either constipated or having Diarrhea... it is possible I do have IBS. Er, number 8 is also very possible especially when I'm busy or too focused on something.. Same situation with number 9.

Well, looking at possible reasons, I'd say the main problem actually lies on my physical bad habits instead of my dietary habits and medical concerns.