Hi, I have IBS and supposedly colonic inertia but I don't seem to go as long as others who have this without a bowel movement. My problem is I have trouble getting it out and then afterwards I get the most excruciating abdominal pain like a colicky baby. My doctor says that the pain is from spasms. So, I can't win whether I do have a b.m. or not, I still get really bad pain and food doesn't seem to make a difference. I used to get less pain if I didn't eat, but now I get it no matter what and as you asked, I also find it strange that the worst pain usually starts around 4-6p.m. No doctors have been able to give me an answer for this. I ws told by an alternative health specialist that this is typical for small intestinal bacterial overgrowth. I discussed this with my doctor and we tried antibiotics and probiotics, but it didn't help. What other symptoms are you having? How bad is your pain? Lately, the pain has been worse during the day then before. I hope others respond to this question as I would be really curious. Good luck.