Inflammatory bowel diseases include both Chron's and Ulcerative colitis, and a group of yet to be determined 'indeterminate colitis." These are lifelong, serious, and yet can be controlled. There are food allergy triggers, dietary triggers, and probably both environmental and genetic components that are probably more important than these signs. But if you have one of these symptoms you need to be seen both by a primary care provider, and when appropriate you may need GI doctor after some testing.
Arthritis, joint aches and pains, particularly of your large joints
Skin, certain rashes are very associated with these conditions, but the presentation varies a lot
Eye inflammation called uveitis, other signs can be light sensitivity, blurred vision, or eye pain.
Oral ulcers, especially occurring on the inside of lips or tongue
Obesity, yes, this one is related more to your gut, your diet, and your genetic make up
Liver problems, particularly fatty liver changes (although those could be linked just to your diet and obesity)
Blood clots, and genetic susceptibility to blood clots.
Lung disease. Like the symptom above, organs, including our gut, need oxygen, and the lungs need to capture it and the blood stream needs to deliver it. Over time these conditions can lead to bowel disease even if they aren't specifically a sign of bowel disease.
Low libido. Too often we think this is secondary to the disease itself, but low libido could be secondary to other problems, and we too often neglect to check for those things less likely to be diagnosed together.
Stress. Ever the trigger for so much that is wrong with our health or what will go wrong if our immune system is not right!