Get your health question answered instantly from our pool of 18000+ doctors from over 80 specialties

166 Doctors Online
Doctor Image
MD
Dr. Andrew Rynne

Family Physician

Exp 50 years

I will be looking into your question and guiding you through the process. Please write your question below.

What causes black stools?

Answered by
Dr.
Dr. Bonnie Berger-Durnbaugh

General & Family Physician

Practicing since :1991

Answered : 2850 Questions

default
Posted on Fri, 11 May 2018 in Digestion and Bowels
Question: Hello,

Is black stool something to worry about, even though I recently had a CT (with barium) that noted a normal stomach, small bowel, and small colon?

It just happened, whereas my bowel movement this morning was a "normal" color. I noticed a very little bit of rectal pain for just a few seconds here and there about an hour ago but that has happened before.

Thank you
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 1 hour later
Brief Answer:
Information

Detailed Answer:
Hello XXXX,

If stool is both black and tarry appearing, then it can be a sign of bleeding from the upper gastrointestinal tract. This is because blood in the stomach is turned black by the acid.

But stool can look black as a result of some supplements including those that have iron in them and Pepto Bismol. But although these things may make stool look black, it won't make them look like tar.

If the stool looks like black tar, then I would suggest talking with your doctor. Although a recent CT was normal, it can't necessarily show a brand new small blood vessel that may bleed. But for the most part, a normal CT will be a good sign that things are ok, i.e. no inflammation or other things that can be worrisome.

I hope this answers your question.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
default
Follow up: Dr. Bonnie Berger-Durnbaugh 37 minutes later
Thank you so much for your response Doctor. Of course I did the wrong thing and googled it before this query and it said “go to the ER immediately” and I thought that that was a little brash. I haven’t taken any supplements like Pepto (because I’ve personally seen that before) but I have been on Ciprofloxacin since Friday. It was a little worrisome considering how out the blue it was, along with very mild internal lower GI sharp stings that occurred a bit tonight; my mind goes right to the worst for whatever reason and I think “hopefully this isn’t some type of GI cancer.” But as you said, the CT would’ve noticed that I would think.
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 26 minutes later
Brief Answer:
Thoughts on this

Detailed Answer:
That you had a normal CT is reassuring.

Was your stool tarry looking? I mean literally looking like black tar?
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
default
Follow up: Dr. Bonnie Berger-Durnbaugh 3 hours later
It was pretty dang black. I would say yes as far as color but not necessarily like tar. I dont know if this would do it, but i very much overindulged on oreos yesterday...maybe thats why the black color atleast?
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 25 minutes later
Brief Answer:
Thoughts on this

Detailed Answer:
Well, Oreos have alkalinized cocoa powder in them which makes them very dark/black, and as not all of our food is entirely broken down, that might be the explanation.

Blood that's been acted on by the stomach acid will look like tar, not like normal poop.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
default
Follow up: Dr. Bonnie Berger-Durnbaugh 16 hours later
Fair enough. Kind of silly but it was all that i could think of. Im curious if this is related to a knawing, sharp groin pain...I awoke last monday with a very sharp right testicle and right pelvic pain (I had a CT and went to a urologist; all was normal. He said prostatitis by elimination). I still feel pressure in my upper right pelvis. I just had a movement and it is like a normal poop but is almost black Could these two be related even with a normal CT and urologist examination? .
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 1 hour later
Brief Answer:
Thoughts on this

Detailed Answer:
It's possible that taking an antibiotic for the presumed prostatitis has altered the gut flora a bit making the color darker. But unless it has a tarry type texture, it isn't likely to be blood so that is good. I think that might be the way these two things are related.

The prostate itself would not put blood in the stool and make it black as it's products would come out the urethra rather than enter the gastrointestinal tract. Black tarry stool gets it's color from way up in the upper GI tract because the stomach acid is what changes the color of the blood to black.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
default
Follow up: Dr. Bonnie Berger-Durnbaugh 8 minutes later
Understood. I didnt know if i had an inguinal hernia or something that was causing GI issues, but as you said, i presume if it were an issue, it would be higher in the tract. I just had another movement and it was back to a brown but was rather tarry. Ive been having on/off tarry stools for a loooooong time and ive had an endoscopy (about 2 months ago; everything was normal) so i would hope that nothing bad is going on with that .
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 1 minute later
Brief Answer:
Questions to clarify

Detailed Answer:
So did you have tarry appearing stools before the upper GI endoscopy or those have happened since then? Was the black tar stools the reason you had the endoscopy? And was it an upper GI endoscopy?
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
default
Follow up: Dr. Bonnie Berger-Durnbaugh 9 minutes later
Before the endoscopy, off and on for years. Endoscopy was for RUQ pain that is resolved by me pressing my finger into it to relieve the ache (see picture for location). Ive had an MRI as well, also normal. It was an upper endoscopy. My GI doc doesnt believe its anything to worry about due to no weigt loss, fatigue, and normal endoscopy & MRI. I would hope that its nothing malignant .
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 45 minutes later
Brief Answer:
Thoughts on this

Detailed Answer:
If it was an upper endoscopy, they would have seen bleeding in the esophagus or stomach. So if you your black stools were caused by bleeding prior to the endoscopy, the gastroenterologist would have seen it.

An MRI would show a tumor.

If you continue to have black stools that are tarry in appearance, and this is different than what you had prior to the upper GI endoscopy, then you could go in to your doctor and have a guaiac test to see if there is presence of blood. The doctor would do a rectal and put a small amount of stool on a special card and then developer liquid on the other side of the card. If there is blood, the developer turns it blue on the other side of the card. You may have had this done before.

But unless this is a new symptom, which you are saying it is not, the tests you have had would have revealed a bleeding blood vessel or ulcer or a tumor.

I looked at the picture and you are pointing pretty far over on the right, so I don't think that would have involved your stomach.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
default
Follow up: Dr. Bonnie Berger-Durnbaugh 9 minutes later
Understood. And thank you so much doctor. Im hoping that my recent BM being back to a brown is a good sign. Ill ask my doctor about the greasy stool (I'd say it happens every 4 movements). I dont have my gallbladder so maybe thats why they can be tarry, depending on the food? I attached the summaries of the MRI and the recent CT as well .
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 5 minutes later
Brief Answer:
Thoughts on this

Detailed Answer:
Yes, being without a gall bladder can change things and may be the cause of the change in stool consistency.

Looking at your CT and MRI, and noting that the urologist was aware of the CT results and concluded that there was proctitis, was he/she aware of the lipomas that were seen on the spermatic cords on the MRI? These are benign fatty growths, but I am wondering if the lipoma on the right might have contributed to or caused the pelvic symptoms you were having. I'm not a urologist so I don't know if that is possible, but I'm just putting together the history your provided and wondering if the urologist knew about those from the MRI.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
default
Follow up: Dr. Bonnie Berger-Durnbaugh 6 minutes later
Thats exactly what i thought! He said that they would probably not contribute to the pain, however, i had another CT a few months before which said that the lipomas were bilateral inguinal hernias. When the urologist scrolled through the CT on his computer, he said that everything looked normal, and prostatitis was diagnosed by everything else being ruled out. So im being told two different things. All i know if that this right side pelvic/testicle pain came on suddenly and brutally. But come five days later after being on Cipro, im 80% better, but theres still a bit of pain and pressure in the right pelvis .
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 11 minutes later
Brief Answer:
Thoughts on this

Detailed Answer:
If the Cipro is helping, then prostatitis as a diagnosis would seem to make sense. I wouldn't be able to read pelvic CTs or MRIs with the accuracy and knowledge a urologist has so I will defer to his experience. If he did not think there were inguinal hernias when he looked at the both the CTs, then there probably isn't any.

If you are doing better from the Cipro, perhaps this will (hopefully) just go away with a little more time.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
default
Follow up: Dr. Bonnie Berger-Durnbaugh 25 minutes later
Attention Dr. XXXXXXX Berger-Burnbaugh

Im sorry. It wouldnt let me respond. My final response, as i dont want to keep pestering:

He only looked at the recent CT (that stated the lipomas, im going to have the other CT sent to the urologist for our appointment on thursday). So being a pain in the butt by asking, regardless of the actual cause, would you as a doctor say that its safe from being anything truly malignant or threatening? Silly i know, because the pain can make it seem worse than it actually is. But i dont want to take any chances.
doctor
Answered by Dr. Bonnie Berger-Durnbaugh 53 minutes later
Brief Answer:
Thoughts on this

Detailed Answer:
I would make sure he sees the MRI too. So that he has everything to compare.

Given all of these imaging studies, and no suggestion of a tumor, I think it is safe to say there isn't a malignancy going on. To cause pain, a tumor has to be of large enough size, and so it should be visible in this region if it is what is causing pain.
Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar
doctor
premium_optimized

The User accepted the expert's answer

Share on
Question is related to
Diseases and Conditions ,   ,   ,  
Lab Tests

Recent questions on  Black stool

doctor1 MD

I am having black specks in faeces, they are not visible at a glance, but when I take faeces in hand and then rub it , it can be seen ,no other symptom, when I press specks they are hard

doctor1 MD

I have black, gassy stool.

doctor1 MD

I am feeling pain in my anal line during bowel movement . stool is blackish. when it was started first time (2 months ago) a little bit of bleeding occurred for a few days. Loss of appetite , weight loss exists. some small reddish patches with itching often viewed anywhere on the body especially in winter. please suggest me.

doctor1 MD

My wife just had a baby girl on the ninth. She has been experiencing sharp lower abdomen pains when drinking fluids, and at times when she doesn t drink. This particular pain did not start until after birth. She experienced some dieriah today that was dark in color. We have wondered if it is connected to her uterous going back to size or if it may be some kind of digestive infection??

doctor1 MD

Hi on Oct 12 I had heavy bleeding and cramping I was 8weeks 6 days pregnant. The Dr said the plasenta was detaching from my uterus and was having a miscarriage . he then did a D&A. Ive had bleeding on and off since and light cramping. Last night the pain was unbearable. i was cramping so bad it felt as if i was in labor. i started sweating a felt as if i was about to pass out from the pain. i went to use the bathroom and my stool was black. i dont know if this is normal after having a miscarriage. the cramping went away about an hour later. today i feel ok but im still worried something might be wrong.

doctor1 MD

Hello my dad is 64 years old and was just dx with liver cancer . He has ascites and edema in his right leg. He won t eat anything except for tea and warm cereal. My mom states he is now passing black stools . All of this just happened or he started showing symptoms In January it now February 23, I m afraid he will continue to go down hill. Does the ascites mean that he has end stage limber cancer. How can I get him to eat.