Liver/Gallbladder worries

Earlier this summer I had a spontaneus pneumothorax and I went to the ER.  My lung ended up reinflating itself but thats not my worries. Since then I have had some worrying symptoms that I've been wondering if they could have something to do with my liver or gallbladder.  Here are the symptoms:

Two times since the lung collapse I've had diarrhea with a bright yellow liquid in it. (Was not the urine)

Also a couple of times I have had kind of yellow tinted stool.

I've had some lower back pain and also recently a little pain behind my right shoulder blade and my upper right side.

I've also lost a little weight since the collapse and I can't tell if its because I have had to quit lifting weights for a while.  I usually weigh around 140 to 145 and now I'm weighing between 135 to 138.  I have never lost weight like that.  And I haven't really had any diet changes recently.  I have noticed a few times that my appetite doesn't seem as big as usual though.

Those are all of my symptoms and I'm just trying to figure out if anythings wrong.  I should also mention that about two years ago, due to my poor decision, I took a pro-hormone supplement to get stronger.  I quit when I figured out how bad it was for me but I just mention that because eversince I took that I've worried if it had any internal effects on my body.  

Advice/Info will be greatly appreciated!!

[Caryopteris]

You need to see your doctor.  It sounds like a gallbladder problem or Celiac disease to me. I'm sure there are other possibilities as well.   You need evaluation.  

[Kaneda2112]

It could be related to kidney stones or gall bladder/bile duct issues. You should get it checked out as weight loss for no apparent reason is a bit of a concern -

From Better Medicine -

"Although the color of stool can be affected by different foods and medications, it is typically brownish due to digestion of bile salts, digestive agents made by the liver and stored in the gallbladder.

A reduction or absence of bile salts can cause the stool to become yellow or pale. Bile salt production can be reduced due to severe liver disease such as hepatitis or cirrhosis. The passage of bile salts into the intestines can be prevented by blockages of the bile ducts due to inflammation, gallstones, or external compression. Pain, especially in the right upper abdomen, fever, nausea, itching, and yellowing of the skin and whites of the eyes can also occur with these conditions.

The pancreas also produces substances important for digestion, including the enzyme lipase, which breaks down fats. Excess fat in the stool can cause yellowish, bulky stool that floats, has an oily or greasy appearance, and smells foul. Inflammation of the pancreas can reduce lipase production. Absence of lipase is uncommon, but can result from pancreatic cancer, severe pancreatic disease, cystic fibrosis, or abnormal lipase production that is present from birth (congenital).

Conditions that affect the intestines, especially those that interfere with fat absorption, can also cause yellow stool. For example, Giardia, a parasite that can be found in waste products and contaminated water, can cause yellow diarrhea, fever, and flu-like symptoms.

Yellow stool is unusual, and may be a symptom of a serious medical condition. Seek immediate medical care (call 911) for severe abdominal pain, stool with blood or pus, high fever (higher than 101 degrees Fahrenheit), significant vomiting, seizures, changes in mental status, or sudden behavior changes. Symptoms of dehydration such as decreased urination, increased thirst, fatigue, and light-headedness also require immediate medical care."